Emergency coronary angioplasty for acute myocardial infarction. Results from a community hospital.

Emergency coronary angioplasty was performed in 127 patients presenting to a community hospital with acute myocardial infarction. Reperfusion and successful dilatation were performed in 117 patients (92%) at 3.3 +/- 1.8 hours from the onset of pain. Eleven patients (8.6%) died, ten patients (7.9%) developed reocclusion, and ten patients (7.9%) required coronary bypass surgery during the initial hospitalization. Late restenosis occurred in 36% (27/76) of patients restudied or 27% (27/100) of patients at risk for restenosis. Ejection fraction improved in patients with patent vs occluded vessels (8.4% +/- 8.2% vs -4.1% +/- 6.0%) and improved most in anterior vs inferior vs posterolateral infarcts (11.0% +/- 8.4% vs 6.8% +/- 6.4% vs 2.6% +/- 7.5%). Posthospitalization follow-up in all patients (mean, 13.4 months) revealed only one late death. Of the patients followed up, 83% had no angina, and 17% of patients had mild angina. Our experience demonstrates that coronary angioplasty for acute myocardial infarction can be performed in the community hospital by an experienced cardiovascular laboratory team with a high success rate, a low reocclusion rate, an improvement in ejection fraction, and an excellent long-term prognosis. The community hospital setting allows early access to patients and creates the potential for early reperfusion and myocardial salvage.

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.

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)

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.

Factors that predict improvement in left ventricular ejection fraction after coronary angioplasty for acute myocardial infarction.

Acute and follow-up angiograms were analyzed in 75 patients with acute myocardial infarction treated with emergency coronary angioplasty to determine factors that might predict improvement in left ventricular ejection fraction. Ejection fraction improved 8.4 +/- 8.2% in 60 patients who maintained patent infarct vessels at follow-up angiography, compared with -4.1 +/- 6.0% in 15 patients who developed reocclusion (p less than .001). In patients with patent infarct vessels, univariate analysis revealed the following significant predictors of improvement in ejection fraction: initial ejection fraction (r = -.38, p less than .003) subtotal vs total stenosis (12.9 +/- 9.3% vs 6.9 +/- 7.3%, p less than .02), infarct vessel (left anterior descending 11.0 +/- 8.4%, right 6.8 +/- 6.4%, circumflex 2.6 +/- 7.5%, p less than .02), and time to follow-up study (less than or equal to 15 days vs greater than 15 days) (4.8 +/- 5.8% vs 9.8 +/- 8.6%, p less than .03). Reperfusion time (less than or equal to 2 hr vs greater than 2 hr) predicted improvement when subtotal stenoses and stuttering infarctions were excluded (10.6 +/- 7.0% vs 4.9 +/- 6.9, p less than .03). Multivariate analysis showed initial ejection fraction and subtotal vs total stenosis to be independent predictors. Patients with anterior infarctions, low initial ejection fractions, and subtotal stenoses or reperfusion times less than or equal to 2 hr are likely to benefit most from coronary angioplasty for acute myocardial infarction.