EFFECTS OF LATE PERCUTANEOUS TRANSLUMINAL CORONARY ANGIOPLASTY OF AN OCCLUDED INFARCT-RELATED CORONARY-ARTERY ON LEFT-VENTRICULAR FUNCTION IN PATIENTS WITH A RECENT (LESS-THAN-6 WEEKS) Q-WAVE ACUTE MYOCARDIAL-INFARCTION (TOTAL OCCLUSION POSTMYOCARDIAL INFARCTION INTERVENTION STUDY [TOMIIS] - A PILOT-STUDY)

The effect of late percutaneous transluminal coronary angioplasty (PTC A) of an occluded infarct-related artery on left ventricular ejection fraction was studied in patients with a recent, first Q-wave myocardia l infarction in a prospective, randomized study. Forty-four patients ( 31 men and 13 women, mean age 58 +/- 12 years) with an occluded infarc t-related coronary artery were randomized to PTCA (n = 25) or no PTCA (n = 19). Patients received acetylsalicylic acid, a beta blocker and a n angiotensin-converting enzyme inhibitor unless contraindicated. Left ventricular ejection fraction was determined at baseline and 4 months . Coronary angiography was repeated at 4 months. Baseline ejection fra ction measured 20 +/- 12 days after myocardial infarction was 45 +/- 1 2% in both groups. PTCA was performed 21 +/- 13 days after the event. The primary PTCA success rate was 72%. One patient in each group died before angiographic follow-up, which was completed in 37 of the remain ing 42 patients (88%; 21 with and 16 without PTCA). At 4 months; the i nfarct-related artery was patent in 43% of PTCA patients and in 19% of no PTCA patients (p = NS). Reocclusion occurred in 40% of patients af ter successful PTCA. Secondary analyses showed that the change in left ventricular ejection fraction was significantly greater in patients w ith a patent infarct-related artery (+9.4 +/- 6.2%) than in those with an occluded artery (+1.6 +/- 8.8%; p = 0.0096). Baseline ejection fra ction also independently predicted improvement in left ventricular eje ction fraction (p = 0.0001). Sustained patency of the infarct-related artery, even when achieved late, may improve left ventricular ejection fraction of patients with a recent Q-wave myocardial infarction. The efficacy of PTCA in this setting is limited by a high reocclusion rate . Further studies are needed to examine methods to minimize reocclusio n and to investigate the effect of PTCA on ventricular function, analy zed on an intention-to-treat basis, in patients with persistent occlus ion of the infarct-related artery after the acute phase of myocardial infarction.