Author + information
- Stelios Karayiannides, MD∗ (, )@karolinskainst,
- Anna Norhammar, MD, PhD,
- Ole Frøbert, MD, PhD,
- Stefan K. James, MD, PhD,
- Bo Lagerqvist, MD, PhD and
- Pia Lundman, MD, PhD
- ↵∗Department of Clinical Sciences, Karolinska Institutet, Danderyd Hospital, 182 88 Stockholm, Sweden
Diabetes mellitus (DM) is associated with an increased complication risk following myocardial infarction (MI) despite improvements in acute coronary care and secondary prevention (1). We investigated the 1-year prognosis in a broad population with concomitant diabetes and ST-segment elevation myocardial infarction (STEMI) that received contemporary treatment.
In the registry-based TASTE (Thrombus Aspiration in ST-Elevation Myocardial Infarction in Scandinavia) trial, 7,244 patients with STEMI who underwent percutaneous coronary intervention (PCI) were randomized to thrombus aspiration and PCI or PCI alone (2). The primary outcome was all-cause mortality at 1 year and the secondary outcomes were hospitalization for recurrent MI or stent thrombosis. Cox proportional hazard regression analysis was used to calculate the hazard ratios (HRs) and 95% confidence intervals (CIs) stratified by diabetes status and treatment. Adjustments were made for age, sex, smoking status, previous MI, previous PCI, creatinine level, body mass index, complete revascularization, radial artery approach, Killip class, 1- or multivessel coronary artery disease and ejection fraction at discharge. Multiple imputation was used to impute adjustment variables with missing data. Time-to-event by diabetes status was analyzed using the Kaplan-Meier method and log-rank test.
In the original trial, 901 patients (12.4%) with DM were reported. However, for this post hoc analysis, an additional 104 patients lacking a registered diabetes diagnosis at the time of inclusion, but receiving glucose-lowering medication at discharge, were reclassified as having DM (n = 1,005, 13.9%). Subgroup analyses did not indicate any different effects of the randomized procedure on the primary outcome of mortality at 1 year in patients with DM than in those without DM (HR: 1.04; 95% CI: 0.69 to 1.58) and neither for recurrent MI nor stent thrombosis. Therefore, all patients with diabetes, irrespective of randomization in TASTE, were studied as 1 cohort.
Patients with DM were older (age 67.6 vs. 66.0 years; p < 0.001) and more often had a history of previous MI (19.9% vs. 10.3%; p < 0.001), previous PCI (17.3% vs. 8.4%; p < 0.001), 3-vessel disease (20.9% vs. 13.6%; p < 0.001), or use of drug-eluting stents (59.0% vs. 48.4%; p < 0.001), but less often achieved complete revascularization (53.5% vs. 61.0%; p < 0.001). There was no difference in the thrombus grade (grades 0 to 5; p = 0.909) and the location of the culprit coronary lesion did not differ between patients with or without DM (left anterior descending artery; 44.5% vs. 44.5%; p = 0.992). The antiplatelet therapy utilized was similar in both groups and ticagrelor or prasugrel was given to 44% of patients, irrespective of diabetes status.
Patients with DM had higher rates of all-cause mortality (9.0% vs. 4.9%; p < 0.001) (Figure 1A) when compared with patients without DM. No significant difference with regard to the occurrence of recurrent MI (4.0% vs. 2.5%) or stent thrombosis (1.0% vs. 0.8%) was observed. Within the DM group, the insulin-treated patients displayed significantly higher 1-year mortality (12.6% vs. 6.6%; p < 0.001) when compared with DM patients without insulin treatment (Figure 1B). Following adjustments, DM was independently associated with increased risk for all-cause mortality at 1 year (HR: 1.57; 95% CI: 1.23 to 2.00; p < 0.001). This risk was more pronounced in patients receiving insulin treatment (HR: 2.04; 95% CI: 1.49 to 2.78; p < 0.001) who, furthermore, were found to have an increased risk of recurrent MI (HR: 1.72; 95% CI: 1.08 to 2.73; p = 0.023) compared with patients without DM. There was no difference in outcomes in patients treated with ticagrelor or prasugrel compared with clopidogrel regardless of diabetes status (HR for all-cause mortality: 1.04; 95% CI: 0.84 to 1.29).
The main finding in this diabetes-oriented analysis of the TASTE trial is that in a real-world STEMI population with contemporary treatment, including acute revascularization with PCI and extensive secondary prevention therapies, DM remains an independent risk factor resulting in an almost doubled 1-year mortality. This adverse prognosis was not explained by differences in thrombus grade, thrombus burden, or a higher rate of stent thrombosis. The excess mortality risk was more pronounced in insulin-treated patients, who also had an increased risk for recurrent MI, whereas non–insulin-treated patients did not have a higher risk for mortality or recurrent MI at 1 year after adjustments. A probable explanation is that insulin-treated patients most likely have a more advanced diabetes disease with longer duration, worse glycemic control, higher risk for hypoglycemia, and underlying macro- and microvascular complications.
Our findings are in line with previous reports on excess mortality risk after MI in patients with diabetes compared with those without diabetes (1). This highlights the need for improved treatment strategies for patients with STEMI and DM, especially for those with insulin treatment.
Please note: Dr. Karayiannides has received an honorarium for an advisory board meeting with AstraZeneca; and speaker fees from AstraZeneca, Merck Sharp & Dohme, and Boehringer Ingelheim. Dr. Norhammar has received an honorarium for advisory board meetings; and speaker fees from AstraZeneca, Novo Nordisk, Merck Sharp & Dohme, Eli Lilly, and Boehringer Ingelheim. Dr. Frøbert has received speaker fess from Abbott. Dr. James has received honoraria from AstraZeneca and The Medicines Company. Dr. Lundman has received an honorarium for advisory board meetings for Sanofi and Boehringer Ingelheim; and speaker fees from AstraZeneca and Sanofi. Dr. Lagerqvist has reported that he has no relationships relevant to the contents of this paper to disclose.
- 2018 American College of Cardiology Foundation