Richard A. Weintraub

Six-month clinical and angiographic follow-up after direct angioplasty for acute myocardial infarction. Final results from the Primary Angioplasty Registry.

After direct angioplasty in the setting of acute myocardial infarction, patients were followed clinically and angiographically for 6 months at six experienced centers to evaluate outcomes. Methods and ResultsOf 258 patients with 6-month follow-up after surviving initial hospitalization, 5 (2%) died, 8 (3%) had nonfatal infarctions, 56 (22%) had chest pain, ofwhom 25 (10%) required hospitalization, and 42 (16%) patients needed repeat angioplasty. Of 203 eligible patients, 154 (76%) had angiographic follow-up. The infarct-related artery remained patent (defined as TIMI 2 or 3 flow) in 87%, while 13% developed reocclusion (TIMI 0 or 1 flow) by 6 months after discharge. Patients with reocclusion were more likely to have adverse events, including 35% with clinically evident reinfarction and 59% requiring repeat angioplasty. The median ejection fraction improvement from acute to follow-up study was 6%, with no improvement in patients with a reoccluded infarct-related artery and an 8% improvement in patients with a patent infarct-related artery. ConclusionsThe positive clinical outcomes recorded immediately after direct angioplasty persisted through 6 months of follow-up. Although the incidence of clinical end points was equivalent to or lower than thrombolytic therapy trials, restenosis is a substantial problem. These findings provide evidence beyond the initial hospitalization that direct angioplasty is a reasonable choice for the treatment of acute myocardial infarction.

Primary coronary angioplasty for acute myocardial infarction (the primary angioplasty registry)

During a 14-month period, 6 experienced centers prospectively enrolled 271 patients into a registry in which percutaneous transluminal coronary angioplasty was the primary treatment for acute myocardial infarction. Patients age > 18 years who presented with ST-segment elevation on the 12-lead electrocardiogram were enrolled if symptom duration was < 12 hours and there was no proclivity for bleeding. An independent core angiographic laboratory processed the angiographic data. Of 271 patients giving informed consent, 245 (90%) were deemed anatomically suitable and underwent angioplasty therapy. Upon leaving the catheterization laboratory 98% of patients had achieved reperfusion; 92% had a residual visual stenosis < or = 50%. Emergency bypass surgery was required in 14 patients (5%) for either failed angioplasty (n = 3) or presumed life-threatening anatomy (n = 11). The in-hospital mortality rate was 4%, whereas the reinfarction rate was 3% and the stroke rate was 1%, with 1 intracranial hemorrhage and 2 embolic events. Bleeding requiring > or = 2 units of blood occurred in 46 patients (18%); 14 of these transfusions were related to coronary artery bypass surgery. Primary angioplasty is associated with a high reperfusion rate, low in-hospital mortality and few recurrent myocardial ischemic events. These results point to the need for a large-scale trial comparing angioplasty with thrombolytic therapy in the setting of acute myocardial infarction.

Outcomes of Direct Coronary Angioplasty for Acute Myocardial Infarction in Candidates and Non-Candidates for Thrombolytic Therapy

Coronary angioplasty without prior thrombolytic therapy was performed in 383 patients with acute myocardial infarction (AMI). Patients were divided into 2 groups depending on whether they were candidates or non-candidates for thrombolytic therapy. Patients were not considered thrombolytic candidates if they: (1) presented in cardiogenic shock, (2) were greater than or equal to 75 years of age, (3) had had coronary artery bypass surgery or, (4) had a reperfusion time of greater than 6 hours. Thrombolytic and nonthrombolytic candidates had similar rates of reperfusion (92 vs 88%), nonfatal reinfarction (6.0 vs 5.9%) and recurrent myocardial ischemia (1.8 vs 0%). Thrombolytic candidates had a lower mortality rate (3.9 vs 24%, p less than 0.0001) and a lower incidence of bleeding (4.6 vs 10.9%, p less than 0.05). Improvement in left ventricular ejection fraction at follow-up angiography was 4.4% in thrombolytic and 10.5% in nonthrombolytic candidates (p less than 0.002). Ejection fraction improved most in patients with anterior wall AMI (7.7% in thrombolytic candidates, 15.1% in nonthrombolytic candidates) and in patients with reperfusion times greater than 6 hours (14.2%). These outcomes suggest that direct coronary angioplasty is a viable alternative method of reperfusion in patients with AMI who are candidates for thrombolytic therapy. Nonthrombolytic candidates are a high-risk group of patients. Direct coronary angioplasty may be beneficial in certain subgroups, especially for patients in cardiogenic shock and for patients presenting greater than 6 hours after the onset of chest pain with evidence of ongoing ischemia.

Importance of infarct-related artery patency for recovery of left ventricular function and late survival after primary angioplasty for acute myocardial infarction

OBJECTIVES The purpose of this study was to evaluate the importance of late infarct-related artery patency for recovery of left ventricular function and late survival after primary angio-plasty for acute myocardial infarction. BACKGROUND Infarct-related artery patency is thought to improve late survival by its effect on preservation of left ventricular function. Patency may also enhance late survival by preventing left ventricular dilation and reducing arrhythmias, independent of myocardial salvage. However, most studies have not shown patency to be an independent predictor of survival when late left ventricular function is taken into account. METHODS We followed up 576 hospital survivors of acute myocardial infarction treated with primary angioplasty for 5.3 years. Ejection fraction and infarct-related artery patency were determined at follow-up catheterization at 6 months. Predictors of late cardiac survival were determined using Cox regression models. RESULTS Patients with patent arteries had more improvement and a better late ejection fraction than patients with occluded arteries (56.3% vs. 47.9%, p = 0.001). In patients with acute ejection fraction < 45%, late survival was better in those with patent versus occluded arteries (89% vs. 44%, p = 0.003), but patency was not a significant predictor after improvement in ejection fraction was taken into account. In patients with a large anterior infarction, patency was a significant independent predictor of late survival. CONCLUSIONS Infarct-related artery patency is important for recovery of left ventricular function, and in patients with acute ejection fraction < 45%, patency is important for late survival. Our data are consistent with the hypothesis that the survival benefit is due primarily to the effect of patency on recovery of left ventricular function. In patients with a large anterior infarction, patency appears to provide an additional late survival benefit independent of myocardial salvage. These observations support the need for additional clinical trials of late reperfusion in patients with a large anterior infarction.

Timing and mechanism of death determined clinically after primary angioplasty for acute myocardial infarction.

We reviewed the timing and mechanism of death in 1,184 consecutive patients with acute myocardial infarction (AMI) treated with primary angioplasty from 1984 to 1995. Of 98 deaths, 48 (49%) occurred early on day 0 or 1. The mechanisms of death were pump failure in 60 patients (61%), reinfarction in 7 patients (7.1%), left ventricular rupture in 5 patients (5.1%), arrhythmia in 3 patients (3.1%), other cardiac causes in 5 patients (5.1%), stroke in 6 patients (6.1%), anoxic encephalopathy in 7 patients (7.1%), and procedure-related deaths in 5 patients (5.1%). The strongest predictors of mortality were cardiogenic shock and unsuccessful reperfusion. Our data indicate that mortality after primary angioplasty, like thrombolytic therapy, is highest in the early hours and is usually due to pump failure. In contrast to thrombolytic therapy, the incidence of death from myocardial rupture and bleeding complications is low. Future treatment strategies will need to focus on the large number of patients with early death due to pump failure, especially patients with cardiogenic shock.

Importance of a patent infarct-related artery for hospital and late survival after direct coronary angioplasty for acute myocardial infarction

The importance of a patent infarct-related artery (IRA) for hospital and late survival was examined in 383 patients with acute myocardial infarction treated with direct coronary angioplasty. At hospital discharge, 317 of 348 patients (91%) had a patent IRA and mean follow-up left ventricular (LV) ejection fraction (EF) was 58%. Cardiac survival after hospital discharge at 1, 3 and 6 years was 99, 95 and 90%. Patency of the IRA was the most important determinant of hospital mortality: patent versus occluded IRA, 5 vs 39% mortality, p less than 0.001. Follow-up LVEF was the most important determinant of late cardiac mortality: follow-up LVEF greater than or equal to 45 versus less than 45%, 2 versus 24% mortality, p less than 0.001. Patency of the IRA was not a significant predictor of late cardiac mortality in the group as a whole: patent versus occluded IRA, 4.7 versus 6.5% mortality, p = 0.67. In the subgroup of patients with depressed initial LVEF less than 45%, patency was a significant predictor of late cardiac mortality: patent versus occluded IRA, 9.2 versus 40% mortality, p = 0.03. Patients with a patent IRA had better recovery of LV function than patients with an occluded IRA (follow-up LVEF 58.5 versus 47.6%, p less than 0.001). When late cardiac mortality was adjusted for differences in follow-up LVEF, patency was no longer a significant predictor of late mortality. Our results indicate patency of the IRA is the most important determinant of hospital survival, and LV function (measured after recovery) is the most important determinant of late cardiac survival.(ABSTRACT TRUNCATED AT 250 WORDS)

Benefit of late coronary reperfusion in patients with acute myocardial infarction and persistent ischemic chest pain

The benefit of thrombolytic therapy given late after the onset of acute myocardial infarction (AMI) has been controversial because of low reperfusion rates and limited myocardial salvage. Persistent chest pain has been used as a criteria for late intervention, but there is little documentation to validate this practice. Clinical outcomes and myocardial salvage were evaluated in 74 patients with AMI and persistent chest pain who underwent late reperfusion (> 6 hours) with direct coronary angioplasty, and these were compared with outcomes in 460 patients with early reperfusion (< or = 6 hours). Patients with late reperfusion had a high infarct artery patency rate (96%), a low hospital mortality rate (5.4%), and a low incidence of reinfarction (1.4%) and recurrent ischemia that were similar to patients with early reperfusion. Patients with late reperfusion had surprisingly good recovery of left ventricular function with improvement in ejection fraction from 50% to 60% at follow-up angiography. Patients with late reperfusion had a greater incidence of collateral flow (45% vs 22%, p < 0.001) and a lower value of peak creatine kinase (1,357 vs 2,057 U/liter, p < 0.001) than patients with early reperfusion. This study emphasizes the importance of persistent chest pain as a marker of continued myocardial viability in patients who present late after AMI. These data suggest that the probable mechanism of continued viability is preserved flow to the infarct zone. Patients with AMI and persistent chest pain may benefit from reperfusion therapy beyond 6 to 12 hours.