Detrimental effects of late aterey opening: Reply

Zimarino et al. have based their conclusions on a comparison of events between the TOAT (1)and GISSOC (2)studies. This comparison is not justified as neither study was powered to examine clinical end points. Furthermore, the inclusion criteria of the trials differed. For example, only 50% of the stented patients within GISSOC had a prior myocardial infarction, whereas in TOAT this was 100%. Moreover, to increase the prevalence of adverse remodelling, the eligibility criteria of TOAT ensured that the stented vessel subtended a large volume of infarcted myocardium with a presumed high microvascular resistance and thus more disordered flow. In addition, 28% of events within TOAT comprised heart failure and stroke, end points that are unlikely to be related to reocclusion. Omitting these end points results in a one-year event rate of 24% in those randomized to intervention, compared to a nine-month event rate of 32% in the corresponding patients within GISSOC.

Undoubtedly, as stent designs improve, late complications will become less frequent; thus, use of drug-eluting stents (3)in TOAT and GISSOC could have resulted in fewer restenoses and reocclusions. The use of post-stent clopidogrel and other thienopyridines for only two weeks is validated and supported by Mishkel et al. (4)and Berger et al. (5).

Unfortunately, Doppler color flow mapping was not a protocol requirement in our study; therefore, quantitative assessment of resting mitral regurgitation is incomplete. Nevertheless, because all patients had single-vessel disease with left anterior descending artery occlusion, the posterior papillary muscle is likely to have been spared, making annular dilation the most probable mechanism of mitral incompetence. We agree that the increased exercise endurance observed in open-artery patients (despite increased left ventricular volumes) is paradoxical, and likely to be mediated through a placebo effect.

• American College of Cardiology Foundation