Author + information
- Received February 16, 1996
- Revision received October 3, 1996
- Accepted October 18, 1996
- Published online February 1, 1997.
- John J Lopez, MDA,
- Kalon K.L Ho, MD, MSc, FACCA,
- Robert C Stoler, MDA,
- Ronald P Caputo, MDA,
- Joseph P Carrozza, MD, FACCA,
- Richard E Kuntz, MD, MSc, FACCA,
- Donald S Baim, MD, FACCA and
- David J Cohen, MD, MScA,*
- ↵*Dr. David J. Cohen, Cardiovascular Division, Beth Israel Hospital, 330 Brookline Avenue, Boston, Massachusetts 02215.
Objectives. We sought to evaluate the immediate angiographic results and intermediate-term follow-up after percutaneous treatment of left main coronary stenoses in the new device era.
Background. Historically, balloon angioplasty of left main coronary stenoses has been associated with high procedural morbidity and poor long-term results. It is not clear whether new devices are more effective in this anatomic setting.
Methods. Between July 1993 and July 1995, we performed initial left main coronary interventions on 46 patients (mean age 67 ± 12 years, 26% women). Quantitative angiography was available for 42 of 46 interventions, and clinical follow-up was obtained for all patients at 1 month, 6 months and 1 year after initial revascularization.
Results. Most interventions (42 of 46) were performed in patients with “protected” coronary stenoses to the left coronary system owing to the presence of one or more patent left main coronary grafts. Seventy-seven percent of screened patients were deemed unsuitable for repeat coronary artery bypass surgery. Procedures performed included stenting in 73% of patients (alone in 30% and after rotational atherectomy in 43%), rotational atherectomy in 58% (alone in 15% and before stenting in 43%), directional atherectomy in 4% and angioplasty alone in 7%. Initial procedural success was achieved in all interventions, with no deaths, myocardial infarctions (creatine kinase, MB fraction >50 IU/liter) or emergent bypass surgery. Follow-up data to date (median duration 9 months, range 6 to 19) demonstrate a 98% overall survival rate and a 6-month event-free survival rate of 78% (six target vessel revascularizations [TVRs], four non-TVRs).
Conclusions. Treatment of protected left main coronary artery stenoses can be accomplished safely and effectively with new device technology. Intermediate-term follow-up demonstrates an acceptably low rate of death, myocardial infarction or repeat revascularization at 6 months and 1 year.
(J Am Coll Cardiol 1997;29:345–52)
Left main coronary artery disease has a poor prognosis with medical treatment ([1, 2]). Based on randomized trials and large registries demonstrating that coronary artery bypass graft surgery leads to striking survival benefits and improved symptomatic status in patients with significant left main coronary artery stenoses, surgical revascularization has become standard therapy for patients with this condition ([3–6]). In contrast, percutaneous transluminal coronary angioplasty (PTCA) has generally been avoided in such patients because of problems such as hemodynamic compromise during balloon inflation, the disastrous consequences of abrupt vessel closure and high rates of restenosis (). In addition, these lesions tend to be heavily calcified and highly elastic, and thus are often technically challenging to treat with conventional balloon angioplasty. Nevertheless, several investigators have attempted PTCA for selected left main coronary lesions with good immediate angiographic and procedural results ([8–13]), particularly in patients with “protected” left main coronary artery stenoses—that is, patients with at least one patent coronary artery bypass graft supplying the left coronary artery system. In general, these series demonstrate typical PTCA results—residual stenoses of 20% to 30%, with restenosis necessitating repeat revascularization in 30% to 40% of patients over the next 6 to 12 months ([8–13]).
Recently, the availability of new devices has rekindled interest in percutaneous treatment of left main coronary artery stenoses. The potential advantages of these devices for left main coronary artery interventions include increased predictability of the immediate result as well as a lower risk of dissection and abrupt closure, which may be life-threatening in this condition. In addition, debulking procedures, such as directional coronary atherectomy (DCA) and percutaneous transcoronary rotational atherectomy (PTCRA) may limit elastic recoil. Stents could also limit elastic recoil and further improve post-treatment minimal lumen diameter (MLD), thereby reducing the incidence of subsequent restenosis in this high risk subset of patients. To date, publications of the results of new device treatment for left main coronary artery stenoses have consisted only of small series and case reports have had limited follow-up ([14–19]). Accordingly, this report describes the immediate procedural outcomes, immediate angiographic results and 1-year follow-up of our experience with percutaneous revascularization of left main coronary stenoses in the new device era.
1.1 Patient group.
Between July 1993 and July 1995, we performed 54 left main coronary artery interventions on 50 patients at Beth Israel Hospital in Boston, representing 2.5% of all interventions during this time. Four such procedures (7%) were performed emergently for acute myocardial infarction, cardiogenic shock or cardiac arrest and were excluded from this study. In addition, four patients underwent a repeat left main coronary intervention for restenosis after PTCA (one patient) or stent placement (two patients) or for subacute thrombosis subsequently treated with stent placement (one patient). These repeat procedures were also excluded from the analysis. Thus, the study group consisted of 46 patients who underwent an initial left main coronary artery intervention. All patients undergoing an elective left main coronary artery intervention had objective evidence of myocardial ischemia and ≥70% visually estimated stenosis of the left main coronary artery.
1.2 Left main coronary artery procedure.
The strategy for treating left main coronary artery stenoses evolved considerably over the study period. Initially, most patients were treated by either Palmaz-Schatz coronary stent implantation (Johnson & Johnson Interventional Systems) (Fig. 1) or balloon angioplasty alone (if the lesion was deemed to be unsuitable for stenting). When high speed rotational atherectomy (Rotablator, Heart Technology) became available at our institution beginning in October 1993, patients with fluoroscopically visible calcification of the left main coronary artery were treated primarily with this procedure. During the last year of the study period, we used a strategy of pretreating most calcified left main coronary stenoses with rotational atherectomy followed by planned coronary stenting whenever feasible (Fig. 2). Stenting was avoided, however, when the reference vessel diameter was <3.0 mm or when the distal runoff was poor.
Directional atherectomy was performed according to standard techniques (). Rotational atherectomy was performed using a “stepped burr” approach as previously described (), generally beginning with a 1.5- or 1.75-mm burr and increasing to a final burr size corresponding to 60% to 80% of the reference vessel diameter. During rotational ablation, the operator attempted to minimize forward pressure to minimize heat generation and maintain a burr speed within 5,000 rpm of the initial “platform.” Left main coronary artery stenting was performed only after pretreatment with either PTCA or PTCRA using Palmaz-Schatz intracoronary stents, Gianturco-Roubin stents (Cook Inc.) or Palmaz-Schatz biliary stents (Johnson & Johnson Interventional Systems) as previously described ([22, 23]). All stenting procedures were concluded with high pressure postdilation at >12 atm, and all balloon inflations were limited to ≤30 s. Prophylactic intra-aortic balloon counterpulsation was used in all patients with unprotected left main coronary stenoses (n = 4) and in other patients with poorly protected left coronary system anatomy, severe left ventricular dysfunction or markedly elevated filling pressures, at the discretion of the operator (n = 9). Intravascular ultrasound imaging was performed during only two interventions (4%).
During left main coronary intervention, all patients received intravenous heparin to maintain an activated clotting time >300 s. No patients received abciximab, dextran or intracoronary thrombolytic therapy. After successful revascularization, all patients who received a stent were treated with aspirin, either dipyridamole (through May 1994) or ticlopidine (after May 1994) and warfarin. Vascular access sheaths were removed 4 to 6 h later when the activated clotting time was <180 s. Once adequate hemostasis was obtained, intravenous heparin was restarted and continued until therapeutic oral anticoagulation (international normalized ratio 2.0 to 3.5) was achieved in all patients. After hospital discharge, warfarin and either dipyridamole or ticlopidine were continued for 4 weeks, and aspirin was continued indefinitely. Further management was guided by the patients’ primary physician.
1.3 Angiographic analysis.
Quantitative angiographic analysis was performed using hand-held digital electronic calipers (Max-Cal, Fowler & NSK), using the 9 or 10F guiding catheter as a reference as previously described (). This method has been previously shown () to be reliably reproducible and to correlate closely with computerized digital image analysis. Preinterventional and postinterventional analyses were performed in the identical working view, generally a shallow right anterior oblique caudal view to maximize visualization of the length and severity of the left main coronary stenosis ([25–27]). The reference vessel was considered to be the diameter of the angiographically normal caliber left main coronary artery proximal (if present) or distal to the lesion. If no angiographically normal segment of the left main coronary artery was present, however, the reference segment was estimated as the largest diameter of the uninvolved proximal left anterior descending coronary artery (LAD) or left circumflex coronary artery (LCx) artery.
Angiographic success was defined as achievement of a residual diameter stenosis ≤50%. Procedural success was defined as angiographic success in the absence of any major complication (in-laboratory death, Q wave myocardial infarction or emergency coronary artery bypass graft surgery).
Clinical follow-up was obtained for all patients at 1 month, 6 months and 1 year after initial revascularization, and annually thereafter to determine each patient’s symptomatic status and need for subsequent revascularization. Follow-up was performed by telephone contact with the patient or his or her primary physician, or both. When necessary, this information was supplemented by a review of hospital discharge summaries, the medical record and coronary angiographic data. Routine angiographic follow-up was not performed during the study period. Target vessel revascularization (TVR) was defined as any coronary artery bypass graft to the left main coronary system or any repeat percutaneous revascularization to the left main coronary artery during follow-up. In contrast, non-TVR was considered to be any subsequent percutaneous revascularization that was performed outside the anatomic boundary of the left main coronary artery.
1.5 Statistical analysis.
Discrete data are presented as frequencies, and continuous data are presented as mean ± SD. Continuous data were compared using the Student ttest (paired or unpaired, as appropriate), and frequencies were compared using the Fisher exact test. A p value <0.05 was considered statistically significant. Estimates of overall and event-free survival were determined from the time of each patient’s first left main coronary intervention using the Kaplan-Meier method ().
2.1 Patient characteristics.
The characteristics of the 46 patients are described in Table 1. The patients’ mean age was 67 ± 12 years, and most patients were men (74%). Ninety-three percent (43 of 46) of the patients had undergone bypass surgery a mean of 5.5 years (range 0.2 to 17.7) before the left main intervention. Six patients (12%) had undergone two or more coronary artery bypass operations. In general, patients were selected for percutaneous intervention after being refused elective or emergent operation (22%), or because of a decision to avoid repeat bypass surgery due to either a patent internal mammary artery (IMA) or the presence of two or more patent grafts to the left coronary artery system. Most patients had Canadian Cardiovascular Society class III (22%) or IV (54%) angina at the time of the left main coronary intervention.
Forty-two (91%) of 46 interventions were performed on patients with protected left main coronary stenoses owing to the presence of one or more patent grafts to the left main coronary system. Sixty-one percent (28 of 46) of interventions were performed in the setting of a single patent graft to either the LAD or LCx system, whereas 30% (14 of 46) of interventions were performed with patent grafts to both the LAD and LCx systems. A patent IMA graft was present in 65% of patients. In those patients with multiple patent grafts, left main coronary intervention was generally performed to revascularize a large intermedius or diagonal branch that was not supplied by a patent graft and that was thought to represent a culprit vessel on either anatomic or electrocardiographic grounds.
The remaining four interventions were performed on unprotected left main coronary stenoses in patients who had been turned down for elective bypass surgery. One of these patients had previously undergone single-vessel bypass surgery to the right coronary artery, and the graft was patent at the time of left main coronary intervention. The native right coronary artery was patent in the other three patients who underwent unprotected left main coronary interventions. There were no angiographically visible collateral channels from the right coronary artery to the left main coronary system in any of these patients.
2.2 In-hospital results and complications.
Left main coronary artery revascularization was performed using a single technique in 26 procedures (56%); these included balloon angioplasty alone in 3 (7%), directional atherectomy in 2 (4%), rotational atherectomy in 7 (15%) and stenting in 14 (30%) (Fig. 3). In addition, rotational atherectomy followed by stenting was used in 20 patients (43%). Stenting was generally performed with the Palmaz-Schatz coronary stent (79%), but eight patients (24%) received Palmaz-Schatz biliary stents, and one patient (2%) received a Gianturco-Roubin stent. Prophylactic intra-aortic balloon pumps were placed in 13 patients (28%). All attempts at left main coronary intervention were successful in reducing the postprocedural residual stenosis to <50% (angiographic success 100%). Moreover, no patients died, required emergency bypass surgery or suffered a Q wave myocardial infarction before hospital discharge. Minor complications occurred in 26% of interventions and consisted primarily of the need for blood transfusion after the procedure (20%). Other minor complications, including surgical vascular repair (6%) and mild (>20 IU/liter, 6%) or moderate (>50 IU/liter, 0%) postprocedure creatine kinase-MB fraction elevation, were infrequent.
2.3 Immediate angiographic results.
Angiographic data were available for 42 of 46 interventions (Table 2). Quantitative angiography could not be performed for the remaining four interventions because of incomplete angiographic information or missing cineangiograms. Aorto-ostial left main coronary stenoses, defined as ≥50% stenosis occurring within 5 mm of the left main coronary artery origin from the aorta, were present in 41% of cases. Moderate or heavy fluoroscopic calcium was present in 74% of cases. In the overall group, the mean preprocedure MLD was 0.98 ± 0.48 mm, with an associated mean percent diameter stenosis of 74 ± 11%. After the left main coronary intervention, the reference diameter was unchanged, but the final MLD increased to 3.27 ± 0.91 mm, resulting in a mean percent diameter stenosis of 10 ± 24%.
2.3.1 Impact of stenting on immediate angiographic results.
Previous studies have demonstrated that stent implantation reduces elastic recoil, thus improving immediate and long-term angiographic results, compared with conventional PTCA (). In our series, patients treated with or without coronary stent implantation had similar reference vessel diameters (3.63 ± 0.80 vs. 3.91 ± 1.04 mm, p = 0.36; Table 3) and similar degrees of calcification (71% vs. 82%, p = 0.48). As expected, stenting of left main coronary stenoses compared with nonstent treatments resulted in larger acute gains (2.52 vs. 1.63 mm, p = 0.004), larger final postprocedure minimal lumen diameters (3.53 ± 0.74 vs. 2.51 ± 0.97 mm, p < 0.001) and lower residual stenoses (3 ± 21% vs. 30 ± 24%, p = 0.001).
Subgroup analysis demonstrated that the benefits of left main coronary stenting were most pronounced for aorto-ostial lesions (Table 4). For aorto-ostial lesions, patients treated with stent implantation achieved a larger final MLD (3.59 ± 0.92 vs. 2.21 ± 0.81 mm, p = 0.006) and a smaller residual stenosis (−7 ± 25 vs. 33 ± 27%, p = 0.008) compared with patients treated without a stent. In contrast, for nonostial left main coronary stenoses, the benefits of stent implantation were less apparent in terms of either MLD (stented 3.50 ± 0.66 vs. nonstented 3.06 ± 1.11 mm, p = 0.27) or residual stenosis (stented 9 ± 17% vs. nonstented 25 ± 20%, p = 0.10). However, given the small number of patients in this subgroup, the power of our study to detect a 16% difference in percent residual stenosis was only 41%.
2.3.2 Impact of rotational ablation.
As noted, mid-way through this series we instituted a strategy of performing rotational atherectomy before stent placement to treat highly complex, calcified left main coronary lesions. In the overallseries, treatment with rotational ablation plus stenting was not associated with a significant improvement in immediate angiographic outcomes (final MLD: 3.43 ± 0.63 mm; percent diameter stenosis: 2 ± 22%) compared with stenting alone (final MLD: 3.67 ± 0.87 mm, p = 0.39; percent diameter stenosis: 5 ± 20%; p = 0.65). Among those lesions with fluoroscopic calcification, however, the use of rotational atherectomy before stent placement did yield somewhat lower residual stenoses (0 ± 20% vs. 14 ± 18%, p = 0.07).
2.4 Clinical follow-up.
Clinical follow-up was available for 100% of treated patients with a minimal follow-up duration of 6 months (median follow-up 9 months, range 6 to 19). At the last follow-up, one patient had died and one patient had suffered a Q wave myocardial infarction (3.5 months after treatment) and subsequently underwent repeat revascularization with PTCA. Overall, TVR was performed in six patients (13%), including one repeat bypass operation and five repeat percutaneous left main coronary interventions. Repeat revascularization of a non–target vessel was required in another four patients (9%).
Fig. 4illustrates overall and event-free survival for the entire cohort. The overall survival rate was 98% at both 6 months and 1 year after the procedure, whereas the event-free survival rate (freedom from death, myocardial infarction or any revascularization) was 78% and 71% at 6 months and 1 year, respectively. Although the overall rate of repeat revascularization was 22% at 6 months, the rate of TVR was only 13%.
This study describes the results of 46 consecutive left main coronary interventions performed during the “new device” era (1993–95) and represents the largest such experience reported to date. In contrast to previous studies of conventional PTCA ([8–13]), we found that treatment of these challenging lesions with a variety of new technologies, including stents and rotational atherectomy, was both safe and effective. Despite the presence of numerous high risk clinical and angiographic characteristics (previous bypass surgery, advanced age and heavy calcification), procedural success in this series was 100%, with no major in-hospital complications. Moreover, the use of specific new device technology resulted in excellent immediate angiographic outcomes. In fact, the mean final diameter stenosis of 10% in this series approaches the best angiographic outcomes that have been reported for treatment of other, more favorable lesion locations with these devices ([20–23]). Finally, clinical follow-up demonstrates that the initial benefit of these procedures was generally maintained. At 1-year follow-up, the overall event-free survival rate was 71%, with target vessel failure in only 13% of patients.
3.1 Comparison with previous studies.
Several previous studies have described the results of left main coronary artery revascularization, primarily using conventional balloon angioplasty (PTCA) ([8–13]). In the largest published series, O’Keefe et al. () performed PTCA of the left main coronary artery in 127 lesions, 97 (76%) of which were “protected.” Although angiographic success was achieved in 94% of elective cases, procedural mortality was 2.4% in “protected” interventions and 9.1% in “unprotected” interventions. Other series have reported similar results ([9–13]). Moreover, although left main coronary artery balloon angioplasty is initially successful in 90% to 95% of patients, the unsuccessful attempts have typically resulted in major complications (death, myocardial infarction or emergency bypass surgery) ([9, 12, 13]), limiting the utility of this procedure. Finally, balloon angioplasty of left main coronary artery stenoses has typically resulted in residual stenoses of 20% to 35%, leading to restenosis and the need for repeat revascularization in 30% to 50% of patients ([9, 12, 13]). For example, O’Keefe et al. () reported that during a mean follow-up period of 20 months, repeat revascularization was performed after 37% of “protected” and 42% of “unprotected” interventions, including TVR in 25% and 38%, respectively. Although the results of DCA for left main coronary artery stenoses have been somewhat more favorable (13% mean residual stenosis, 89% 6-month event-free survival rate), its use remains limited by technical difficulty in delivering the rigid atherectomy housing into these often calcified lesions ().
Compared with these published data, our results using a lesion-specific approach that begins with rotational atherectomy for calcified lesions and generally finishes with adjunctive coronary stenting with high pressure balloon dilation, are quite favorable. Using this approach, we achieved procedural success in 100% of patients with a low (10%) mean residual stenosis and no major complications. Given the excellent immediate angiographic results in these procedures, the relatively low (13%) incidence of subsequent TVR is not surprising.
3.2 Device selection/technical considerations.
Despite the relatively small size of our series, certain useful insights may be derived from our experience. The use of coronary stents, either alone or after initial rotational atherectomy, produces the best immediate angiographic results (Table 3). These findings are consistent with the benefits that have been demonstrated for stenting in other lesion locations ([29, 30]). Not surprisingly, we found that the benefits of stenting to treat left main coronary artery stenoses were most pronounced for aorto-ostial lesions (Table 4), which are generally troubled by elastic recoil ([14, 26, 31–35]). In our series, stenting for aorto-ostial disease was associated with much lower mean residual stenoses than any other nonstent treatment (−7% vs. 33%, p = 0.008). For nonostial lesions, however, the immediate angiographic benefits of stenting were fewer.
Although the benefits of stenting for aorto-ostial left main coronary lesions are striking, these procedures are nonetheless challenging. Proper stent positioning is critical to resist recoil and requires identification of an angiographic view that precisely defines the limits of the aortic wall. To avoid missing the true ostium, we have generally favored an approach of allowing the stent to protrude 1 to 2 mm into the aortic lumen and using a balloon to “flare” the end of the stent against the aortic wall. In addition, the use of biliarystents, given their greater radial strength and radiopacity, offers certain advantages in this location.
Finally, our data suggest that pretreatment of heavily calcified left main coronary artery lesions with rotational atherectomy before stenting may improve stent deliverability and expansion, with improved short-term results. Specifically, the use of a combination of rotational ablation and stenting for calcified lesions was associated with a lower postprocedure residual stenosis than stenting alone (0% vs. 14%, p = 0.07). This appears to be a classic example of “transdevice synergy,” in which pretreatment with rotational atherectomy debulks and decalcifies the lesion so as to facilitate optimal stent deployment (). Despite their lower postprocedure residual stenoses, patients treated with rotational atherectomy had a similar need for later TVR as those patients treated without rotational atherectomy (15% vs. 11%, p = 0.61). Nonetheless, one might speculate that by permitting optimal stent deployment at lower inflation pressures and allowing the achievement of lower residual stenoses, this technique might be associated with less deep tissue injury, less dissection and possibly less neointimal proliferation and restenosis ([37–39]). These potential benefits of transdevice synergy, however, remain unproved, and controlled trials will be necessary to address this issue directly.
3.3 Clinical implications.
Our findings have several important implications for the treatment of left main coronary artery disease. In patients with myocardial ischemia due to protectedleft main coronary artery stenoses, our results suggest that the use of new coronary devices in a lesion-specific manner is a safe and effective form of coronary revascularization, and may be superior to the results offered by conventional balloon angioplasty. Given the high risk associated with repeat bypass operations in such patients (who often have a patent IMA graft, poor distal targets and depressed left ventricular function) (), percutaneous revascularization with new devices may therefore represent the current treatment of choice.
Nonetheless, widespread adoption of stenting or other new device use for treatment of unprotectedleft main coronary stenoses in patients who are acceptable surgical risks would be premature at this time. Over the past 25 years, bypass surgery has demonstrated excellent short-term and long-term clinical results for this condition, with procedural mortality in the 1% to 2% range and 3-year survival rates >90% ([1, 3–6]). In contrast, PTCA of unprotected left main coronary stenoses has demonstrated a short-term mortality as high as 21%, even when the procedure is performed with percutaneous cardiopulmonary support (). Although the use of stenting has led to a reduction in short-term ischemic complications of PTCA, even optimal stenting currently has restenosis rates of 13% to 20% (). In the setting of an unprotected left main coronary lesion, the clinical impact of restenosis is unclear, but might well present as cardiogenic shock or sudden death in this subset of patients. Thus it is unlikely that percutaneous revascularization will replace bypass surgery for the treatment of unprotected left main coronary artery disease, at least until the problem of restenosis has been virtually eliminated. Nonetheless, in patients with severe left main coronary artery disease who are poor surgical candidates, cautious application of new device percutaneous revascularization (i.e., stenting) may be appropriate ().
3.4 Study limitations.
This study has several important limitations. Although this is the largest series of patients treated with new devices for revascularization of left main coronary stenoses, the number of patients is still small and represents an early portion of the “learning curve” for these procedures. As with any observational study, it is possible that our results are confounded by unmeasured covariates. Thus our conclusions regarding the benefits of stenting for ostial lesions and the benefits of rotational ablation for calcified lesions should be viewed as preliminary and await confirmation by other, larger series or ideally in a controlled clinical trial. Nonetheless, these observations are reasonable from a pathophysiologic viewpoint and mirror the benefits seen with these devices in other coronary locations ([21, 29, 30, 33, 34]). The duration of clinical follow-up (median 9 months) in our study was somewhat limited, and it is possible that longer follow-up will demonstrate additional clinical events. Recent data, however, suggest that the restenosis process after stenting is time-limited and that little progression occurs beyond 6 months ([42–44]). Thus, any subsequent events or revascularization procedures are likely to be due to progression of disease elsewhere in the coronary artery tree.
Finally, the number of patients with unprotectedleft main coronary lesions in the study cohort is too small (four patients) to evaluate the merits of this procedure. Based on the excellent results we observed in anatomically similar protectedleft mains, however, selective treatment of patients with unprotected ostial or mid left main coronary lesions (not including the LAD/LCx bifurcation) might be considered by experienced centers in patients viewed as high risk for surgery.
To our knowledge, this study provides the first comprehensive assessment of the impact of new device technology on the percutaneous revascularization of patients with protected and unprotected left main coronary artery disease. It demonstrates that a lesion-specific approach incorporating rotational ablation, coronary stents and adjunctive balloon dilation produces excellent immediate angiographic results and low procedural complications in the treatment of these challenging and complex lesions. Moreover, intermediate-term follow-up demonstrates good clinical outcomes, including a 1-year survival rate of 98% and freedom from death, myocardial infarction or repeat TVR at 6 months of 87%. More studies are needed, however, to elucidate more fully the role of these devices in various patient subsets, including “unprotected” and emergent left main coronary interventions, and to better define criteria for optimal device selection.
☆ Drs. Lopez and Ho are affiliated with the Beth Israel Hospital–Harvard/MIT Health Science and Technology Program, in collaboration with Pfizer, Inc., Groton, Connecticut. Dr. Cohen was supported by a Clinician-Scientist Award From the American Heart Association, Dallas, Texas. This study was presented in part at the 68th Scientific Sessions of the American Heart Association, Anaheim, California, November 1995.
- directional coronary atherectomy
- internal mammary artery
- left anterior descending coronary artery
- left circumflex coronary artery
- mimimal lumen diameter
- percutaneous transluminal coronary angioplasty
- percutaneous transcoronary rotational atherectomy
- target vessel revascularization
- Received February 16, 1996.
- Revision received October 3, 1996.
- Accepted October 18, 1996.
- The American College of Cardiology
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