Journal of the American College of Cardiology
Detrimental effects of late artery opening
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In reference to the recent study by Yousef et al. (1)in the Journal,we agree that percutaneous coronary interventions (PCI) for an occluded artery late after an acute myocardial infarction are not risk-free procedures, and even an immediate angiographic success may be harmful in the long term. The investigators attribute detrimental effects of late reperfusion—significantly greater one-year left ventricular (LV) end-systolic and end-diastolic volumes—to periprocedural microembolization of collateral vessels. However, as reported in the study limitations, the researchers did not routinely measure cardiac markers after PCI; therefore, no proof for such a causative mechanism exists.
An alternative explanation for this finding is that the adverse effect on remodelling of the invasive strategy is not related to the PCI procedure itself but to the extremely high rate of late events occurring in these patients in relation to a suboptimal treatment. Here the 50% rate of adverse event at one year is far higher than the 32% rate reported after stent implantation in occluded arteries, even using the now outdated Palmaz-Schatz stents and warfarin therapy (2). The use of NIR stents (3)and the suboptimal (two weeks) duration of clopidogrel therapy might be advocated as a cause of higher-than-expected restenosis and reocclusion rates in the study by Yousef et al. (1).
Moreover, LV volumes are certainly a better surrogate end point than exercise tolerance, but improvements in exercise duration and peak rate-pressure products in the intervention group are unexpectedly discordant from echocardiographic findings. Changes in mitral regurgitation severity may contribute to limitation of exercise capacity (4). The assessment of mitral regurgitation in this setting could be extremely helpful in clarifying whether detrimental effects on remodelling are uniformly found in the entire cohort of patients who underwent PCI or only in the subgroup of patients who experienced adverse events.
- American College of Cardiology Foundation
