Effects of sodium nitroprusside on left ventricular diastolic pressure-volume relations.

The effect of sodium nitroprusside on the relationship between left ventricular pressure and volume during diastole was studied in 11 patients with congestive heart failure. Nitroprusside was infused to lower mean arterial pressure approximately 20-30 mm Hg. High fidelity left ventricular pressures were recorded in all patients simultaneously with left ventricular cineangiography (biplane in eight and single plane in three patients), allowing precise measurement of pressure and volume throughout the cardiac cycle. Left ventricular diastolic pressure-volume curves were constructed in each patient from data obtained before and during nitroprusside infusion. In 9 of 11 patients there was a substantial downward displacement of the diastolic pressure-volume curve during nitroprusside infusion, with left ventricular pressure being lower for any given volume with nitroprusside. Serial left ventricular cineangiograms performed 15 min apart in six additional subjects who did not receive sodium nitroprusside showed no shift in the diastolic pressure-volume relation, indicating that the shift seen with nitroprusside was not due to the angiographic procedure itself. A possible explanation for the altered diastolic pressure-volume relationships with nitroprusside might be a direct relaxant effect of nitroprusside on ventricular muscle, similar to its known relaxant effect on vascular smooth muscle. Alternatively, nitroprusside may affect the diastolic pressure-volume curve by affecting viscous properties or by altering one or more of the extrinsic constraints acting upon the left ventricle.

Normal flow (TIMI-3) before mechanical reperfusion therapy is an independent determinant of survival in acute myocardial infarction: analysis from the primary angioplasty in myocardial infarction trials.

BACKGROUND: Whereas survival after lytic therapy for myocardial infarction is strongly dependent on early administration, it is unknown whether the otherwise excellent outcomes in patients undergoing primary PTCA for acute myocardial infarction, in whom TIMI-3 flow rates of >90% may be achieved, can be further improved by early reperfusion. METHODS AND RESULTS: Among 2507 patients enrolled in 4 PAMI trials undergoing primary PTCA, spontaneous reperfusion (TIMI-3 flow) was present in 16% at initial angiography. Compared with patients without TIMI-3 flow, those with TIMI-3 flow before PTCA had greater left ventricular ejection fraction (57+/-10% versus 53+/-11%, P=0.003) and were less likely to present in heart failure (7.0% versus 11.6%, P=0.009). Patients with initial TIMI-3 flow had significantly lower in-hospital rates of mortality, new-onset heart failure, and hypotension and had a shorter hospital stay. Cumulative 6-month mortality was 0.5% in patients with initial TIMI-3 flow, 2.8% with TIMI-2 flow, and 4.4% with initial TIMI-0/1 flow (P=0.009). By multivariate analysis, TIMI-3 flow before PTCA was an independent determinant of survival (odds ratio 2.1, P=0.04), even when corrected for by postprocedural TIMI-3 flow. CONCLUSIONS: Patients undergoing primary PTCA in whom TIMI-3 flow is present before angioplasty present with greater clinical and angiographic evidence of myocardial salvage, are less likely to develop complications related to left ventricular failure, and have improved early and late survival. These data warrant prospective randomized trials of pharmacological strategies to promote early reperfusion before definitive mechanical intervention in acute myocardial infarction.

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.

Importance of time to reperfusion for 30-day and late survival and recovery of left ventricular function after primary angioplasty for acute myocardial infarction.

OBJECTIVES: The purpose of this study was to evaluate the importance of time to reperfusion for outcomes after primary angioplasty for acute myocardial infarction. BACKGROUND: Survival benefit of thrombolytic therapy for acute myocardial infarction is strongly dependent on time to treatment. Recent observations suggest that time to treatment may be less important for survival with primary angioplasty. METHODS: Consecutive patients (n=1,352) with acute myocardial infarction treated with primary angioplasty were followed for up to 13 years. Paired acute and follow-up ejection fraction data were obtained at cardiac catheterization in 606 patients. RESULTS: Reperfusion was achieved within 2 h in 164 patients (12%). Thirty-day mortality was lowest with early reperfusion (4.3% at <2 h vs. 9.2% at > or = 2 h, p=0.04) and was relatively independent of time to reperfusion after 2 h (9.0% at 2 to 4 h, 9.3% at 4 to 6 h, 9.5% at >6 h). Thirty-day-plus late cardiac mortality was also lowest with early reperfusion (9.1% at <2 h vs. 16.3% at > or = 2 h, p=0.02) and relatively independent at time to reperfusion after 2 h (16.4% at 2 to 4 h, 16.9% at 4 to 6 h, 15.6% at >6 h). Improvement in left ventricular ejection fraction was greatest in the early reperfusion group and relatively modest after 2 h (6.9% at <2 h vs. 3.1% at > or =2 h, p=0.007). CONCLUSIONS: Time to reperfusion, up to 2 h, is important for survival and recovery of left ventricular function. After 2 h, recovery of left ventricular function is modest and survival is relatively independent of time to reperfusion. These data suggest that factors other than myocardial salvage may be responsible for survival benefit in patients treated with primary angioplasty after 2 h.

Quality of life after balloon angioplasty or stenting for acute myocardial infarction. One-year results from the Stent-PAMI trial.

OBJECTIVES: The goal of this study was to compare the impact of primary stenting or percutaneous transluminal coronary angioplasty (PTCA) on health-related quality of life (HRQOL) in patients undergoing direct angioplasty for acute myocardial infarction (AMI). BACKGROUND: Previous studies have demonstrated that coronary stenting reduces clinical and angiographic restenosis compared with PTCA. However, the impact of stenting on HRQOL from the patient's perspective remains unknown. METHODS: We administered the Seattle Angina Questionnaire and the Medical Outcomes Study Short-form Survey at 1, 6 and 12 months after initial treatment to all North American patients in the Stent-Primary Angioplasty for Myocardial Infarction trial (Stent-PAMI) (n = 509)-a randomized trial comparing primary stenting to conventional PTCA for patients with AMI. RESULTS: At one month, most HRQOL measures were similar for the two groups, but stent patients reported less bodily pain than PTCA patients (p = 0.03). At six-month follow-up, stenting resulted in significant improvements in several dimensions of HRQOL including reduced anginal frequency and bodily pain as well as improved disease perception (all p < or = 0.03) and a trend towards better anginal stability (p = 0.056). By 12-month follow-up, however, none of these differences remained statistically significant. These differences in HRQOL were largely explained by the greater need for ischemia-driven target-vessel repeat revascularization procedures in PTCA patients during the first six months (16.0% vs. 6.2%, p < 0.001). CONCLUSIONS: In patients undergoing revascularization for AMI, initial stent placement is associated with improvements in several dimensions of health status during the first six months of follow-up. In the absence of differences in mortality, these findings add to the overall argument in favor of initial stenting in patients treated with mechanical reperfusion for myocardial infarction.

Clinical and angiographic outcomes in patients with previous coronary artery bypass graft surgery treated with primary balloon angioplasty for acute myocardial infarction. Second Primary Angioplasty in Myocardial Infarction Trial (PAMI-2) Investigators.

OBJECTIVES: We sought to characterize the presenting characteristics of patients with previous coronary artery bypass graft surgery (CABG) and acute myocardial infarction (AMI) and to determine the angiographic success rate and clinical outcomes of a primary percutaneous transluminal coronary angioplasty (PTCA) strategy. BACKGROUND: Patients who have had previous CABG and AMI comprise a high risk group with decreased reperfusion success and increased mortality after thrombolytic therapy. Little is known about the efficacy of primary PTCA in AMI. METHODS: Early cardiac catheterization was performed in 1,100 patients within 12 h of onset of AMI at 34 centers in the prospective, controlled Second Primary Angioplasty in Myocardial Infarction trial (PAMI-2), followed by primary PTCA when appropriate. Data were collected by independent study monitors, end points were adjudicated and films were read at an independent core laboratory. RESULTS: Of 1,100 patients with AMI, 58 (5.3%) had undergone previous CABG. The infarct-related vessel in these patients was a bypass graft in 32 patients (55%) and a native coronary artery in 26 patients. Compared with patients without previous CABG, patients with previous CABG were older and more frequently had a previous myocardial infarction and triple-vessel disease. Coronary angioplasty was less likely to be performed when the infarct-related vessel was a bypass graft rather than a native coronary artery (71.9% vs. 89.8%, p = 0.001); Thrombolysis in Myocardial Infarction trial (TIMI) flow grade 3 was less frequently achieved (70.2% vs. 94.3%, p < 0.0001); and in-hospital mortality was increased (9.4% vs. 2.6%, p = 0.02). As a result, mortality at six months was 14.3% versus 4.1% in patients with versus without previous CABG (p = 0.001). By multivariate analysis, independent determinants of late mortality in the entire study group were advanced age, triple-vessel disease, Killip class and post-PTCA TIMI flow grade <3. CONCLUSIONS: Reperfusion success of a primary PTCA strategy in patients with previous CABG, although favorable with respect to historic control studies, is reduced as compared with that in patients without previous CABG. New approaches are required to treat patients with previous CABG and AMI, especially when the infarct-related vessel is a diseased saphenous vein graft.

Prospective, multicenter study of the safety and feasibility of primary stenting in acute myocardial infarction: in-hospital and 30-day results of the PAMI stent pilot trial. Primary Angioplasty in Myocardial Infarction Stent Pilot Trial Investigators.

OBJECTIVES: The goals of this study were to examine the safety and feasibility of a routine (primary) stent strategy in acute myocardial infarction (AMI). BACKGROUND: Limitations of reperfusion by primary percutaneous transluminal coronary angioplasty (PTCA) in AMI include in-hospital recurrent ischemia or reinfarction in 10% to 15% of patients, restenosis in 37% to 49% and late infarct-related artery reocclusion in 9% to 14%. By lowering the residual stenosis and sealing dissection planes created by PTCA, primary stenting may further improve short- and long-term outcomes after mechanical reperfusion. METHODS: Three hundred twelve consecutive patients treated with primary PTCA for AMI at nine international centers were prospectively enrolled. After PTCA, stenting was attempted in all eligible lesions (vessel size 3.0 to 4.0 mm; lesion length < or = 2 stents; and the absence of giant thrombus burden after PTCA, major side branch jeopardy or excessive proximal tortuosity or calcification). Patients with stents were treated with aspirin, ticlopidine and a 60-h tapering heparin regimen. RESULTS: Stenting was attempted in 240 (77%) of 312 patients, successfully in 236 (98%), with Thrombolysis in Myocardial Infarction grade 3 flow restored in 230 patients (96%). Patients with stents had low rates of in-hospital death (0.8%), reinfarction (1.7%), recurrent ischemia (3.8%) and predischarge target vessel revascularization for ischemia (1.3%). At 30-day follow-up, no additional deaths or reinfarctions occurred among patients with stents, and target vessel revascularization was required in only one additional patient (0.4%). CONCLUSIONS: Primary stenting is safe and feasible in the majority of patients with AMI and results in excellent short-term outcomes.

A prospective, randomized evaluation of prophylactic intraaortic balloon counterpulsation in high risk patients with acute myocardial infarction treated with primary angioplasty. Second Primary Angioplasty in Myocardial Infarction (PAMI-II) Trial Investigators.

OBJECTIVES: A large, international, multicenter, prospective, randomized trial was performed to determine the role of prophylactic intraaortic balloon pump (IABP) counterpulsation after primary percutaneous transluminal coronary angioplasty (PTCA) in acute myocardial infarction (AMI). BACKGROUND: Previous studies have suggested that routine IABP use after primary PTCA reduces infarct-related artery reocclusion, augments myocardial recovery and improves clinical outcomes. METHODS: Cardiac catheterization was performed in 1,100 patients within 12 h of onset of AMI at 34 clinical centers. Clinical and angiographic variables were used to stratify patients undergoing primary PTCA into high and low risk groups. High risk patients were then randomized to 36 to 48 h of IABP (n = 211) or traditional care (n = 226). The study had 80% power to detect a reduction in the primary end point from 30% to 20%. RESULTS: There was no significant difference in the predefined primary combined end point of death, reinfarction, infarct-related artery reocclusion, stroke or new-onset heart failure or sustained hypotension in patients treated with an IABP versus those treated conservatively (28.9% vs. 29.2%, p = 0.95). The IABP strategy conferred modest benefits in reduction of recurrent ischemia (13.3% vs. 19.6%, p = 0.08) and subsequent unscheduled repeat catheterization (7.6% vs. 13.3%, p = 0.05) but did not reduce the rate of infarct-related artery reocclusion (6.7% vs. 5.5%, p = 0.64), reinfarction (6.2% vs. 8.0%, p = 0.46) or mortality (4.3% vs. 3.1%) and was associated with a higher incidence of stroke (2.4% vs. 0%, p = 0.03). IABP use did not result in enhanced myocardial recovery as assessed by paired admission to predischarge and 6-week rest and exercise left ventricular ejection fraction. CONCLUSIONS: In contrast to previous studies, a prophylactic IABP strategy after primary PTCA in hemodynamically stable high risk patients with AMI does not decrease the rates of infarct-related artery reocclusion or reinfarction, promote myocardial recovery or improve overall clinical outcome.

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.

Combined hemodynamic-ultrasonic method for studying left ventricular wall stress: comparison with angiography.

Calculation of left ventricular wall stress in man has traditionally required angiographic and left ventricular pressure measurement, making study of interventions difficult. We have developed a combined hemodynamic-ultrasonic technique for measuring left ventricular meridional wass stress (sigma m) throughout the cardiac cycle. Simultaneous measurements of left ventricular pressure, ultrasonically determined wall thickness (h[echo]), and minor axis (D[echol]) were made during cardiac catheterization in nine subjects, three with chronic left ventricular pressure overload, four with left ventricular volume overload and two with normal left ventricular function. Within 30 minutes, left ventricular cineangiography was performed in each subject and angiographic wall thickness (h[angio]) and minor axis (D[angio]) were measured. Comparison of values for each subject throughout the cardiac cycle (average 18 data points/cycle) yielded close correlation: For D(echo) versus D(angio), r values ranged from 0.82 to 0.98 whereas for h(echo) versus h(angio), r values ranged from 0.56 to 0.98 for the nine subjects. Meridional wall stress was calculated after the method of Sandler and Dodge as PRi2/h(2Ri + h), where Ri equals the inner wall radius, calculated as D/2 for both ultrasonic and angiographic methods. Agreement between ultrasonic and angiographic methods was excellent in each subject, with close superimposition of the stress-time plots constructed by the different techniques. In summary, a new method for measurement of left ventricular wall stress has been developed and validated by comparison with an angiographic reference standard. This method has potential advantages, including the ability to study meridional wall stress continuously and to assess its response to serial interventions.

Effusive-constrictive hemodynamic pattern due to neoplastic involvement of the pericardium.

Eight patients with metastatic malignancy of the pericardium who demonstrated the hemodynamics of subacute effusive-constrictive pericarditis were studied. All patients had clinical evidence of cardiac tamponade due to malignant pericardial effusion and were referred for therapeutic pericardiocentesis. In six in whom pericardiocentesis was successfully performed, right atrial pressure remained elevated after pericardiocentesis and return of the intrapericardial pressure to zero; in these patients, hemodynamic data were initially compatible with tamponade but suggested constriction after removal of the pericardial fluid. In the remaining two patients, echocardiography revealed pericardial fluid, but attempted pericardiocentesis was unsuccessful. In these two patients, the hemodynamic data suggested pericardial constriction; subsequent pathologic examination revealed neoplastic involvement of the visceral pericardium. Thus, subacute effusive-constrictive pericarditis, previously recognized as a complication of tuberculosis or mediastinal radiation, may also be due to metastatic malignancy. The syndrome can readily be demonstrated when right heart catheterization is performed in conjunction with pericardiocentesis.

Intra-aortic balloon counterpulsation before primary percutaneous transluminal coronary angioplasty reduces catheterization laboratory events in high-risk patients with acute myocardial infarction.

The benefit of intra-aortic balloon counterpulsation (IABC) before primary percutaneous transluminal coronary angioplasty (PTCA) for acute myocardial infarction in high-risk patients has not been well documented. Consecutive patients (n = 1,490) with acute myocardial infarction treated with primary PTCA from 1984 to 1997 were prospectively enrolled in an ongoing registry. Catheterization laboratory events occurred during or after intervention in 88 patients (5.9%), including ventricular fibrillation in 59 patients (4.0%), cardiopulmonary arrest in 46 patients (3.1%), and prolonged hypotension in 33 patients (2.2%). Cardiogenic shock was the strongest predictor of catheterization laboratory events (odds ratio [OR] 2.18, 95% confidence intervals [CI] 1.58 to 3.02) followed by low ejection fraction (<30%) (OR 1.51, 95% CI 1.06 to 2.15) and congestive heart failure (CHF) (OR 1.45, 95% CI 1.01 to 2.07). IABC used before intervention was associated with fewer catheterization laboratory events in patients with cardiogenic shock (n = 1 19) (14.5% vs. 35.1%, p = 0.009), in patients with CHF or low ejection fraction (n = 119) (0% vs. 14.6%, p = 0.10), and in all high-risk patients combined (n = 238) (1 1.5% vs. 21.9%, p = 0.05). IABC was a significant independent predictor of freedom from catheterization laboratory events (OR 0.48, 95% CI 0.29 to 0.79). These data support the use of IABC before primary PTCA for acute myocardial infarction in all patients with cardiogenic shock, and suggest that prophylactic IABC may also be beneficial in patients with CHF or depressed left ventricular function.

Benefit of coronary reperfusion before intervention on outcomes after primary angioplasty for acute myocardial infarction.

Primary percutaneous transluminal coronary angioplasty has become the preferred reperfusion strategy for acute myocardial infarction in most institutions with interventional facilities and experienced operators. The benefit of establishing coronary reperfusion, with or without pharmacologic therapy, before primary angioplasty has not been established. Consecutive patients (n = 1,490) with acute myocardial infarction treated with aspirin and heparin followed by primary percutaneous transluminal coronary angioplasty were followed for 13 years. Follow-up angiography was obtained in 737 patients at 7.7 months. Thrombolysis In Myocardial Infarction (TIMI) 2 to 3 flow in the infarct artery at initial angiography was present in 18.3% of patients, and TIMI 0 to 1 flow in 81.7% of patients. Baseline variables were similar between the 2 groups, except patients with initial TIMI 2 to 3 flow had significantly less cardiogenic shock (1.7% vs 9.4%, p <0.0001) and a lower incidence of depressed ejection fraction <40% (12.6% vs 19.9%, p = 0.007). Procedural success was better in patients with initial TIMI 2 to 3 flow (97.4% vs 93.8%, p = 0.02), and catheterization laboratory events were less frequent. Patients with initial TIMI 2 to 3 flow had lower peak creatine kinase values (1,328 vs 2,790 IU/L, p <0.0001), higher acute ejection fraction (54.3% vs 51.6%, p = 0.05), higher late ejection fraction (59.2% vs 54.9%, p = 0.004), and lower 30-day mortality (4.8% vs 8.9%, p = 0.02). These data indicate that when reperfusion occurs before primary angioplasty, outcomes are strikingly better with less cardiogenic shock, improved procedural outcomes, smaller infarct size, better preservation of left ventricular function, and reduced mortality. This should encourage new strategies to establish reperfusion before "primary" angioplasty with "catheterization laboratory friendly" platelet inhibitors and/or low-dose thrombolytic drugs.

Role of cardiac surgery in the hospital phase management of patients treated with primary angioplasty for acute myocardial infarction.

Although cardiac surgery is performed in approximately 10% of acute myocardial infarction (AMI) patients undergoing a primary percutaneous transluminal coronary angioplasty (PTCA) reperfusion strategy before discharge, the indications for and timing of operative revascularization, and the short- and long-term outcomes after surgery have not been characterized. In the prospective, controlled Primary Angioplasty in Myocardial Infarction-2 trial, cardiac catheterization was performed in 1,100 patients within 12 hours of onset of AMI at 34 centers, followed by primary PTCA when appropriate. Cardiac surgery was performed before hospital discharge in 120 patients (10.9%), electively in 42.6%, and on an urgent or emergent basis in 57.4%. Surgery was performed in 6.1% of 982 patients after primary PTCA (although emergently for failed PTCA in only 4 cases [0.4%]), and in 53 of 118 patients (44.9%) not undergoing primary PTCA. Patients requiring surgery were older, and more frequently had diabetes and 3-vessel disease than those managed nonoperatively. Internal mammary artery grafts were placed in only 31% of patients. In-hospital mortality was 6.4% in patients undergoing urgent/emergent surgery, 2.0% after elective surgery, and 2.6% in patients not undergoing surgery (p = NS). After multivariate correction for baseline risk factors, early and late survival free of reinfarction were similar in patients undergoing versus not undergoing in-hospital cardiac surgery. Thus, the appropriate use of coronary artery bypass graft surgery in the peri-infarction period is an integral component of the primary PTCA approach, and is frequently used to optimize the prognosis of a high-risk AMI cohort with unfavorable baseline features. The implications for the performance of primary PTCA in AMI at centers without on-site surgical facilities are discussed.

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.

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.

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 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)

Angiographic and clinical characteristics associated with increased in-hospital mortality in elderly patients with acute myocardial infarction undergoing percutaneous intervention (a pooled analysis of the primary angioplasty in myocardial infarction trials).

Advanced age is associated with increased mortality in acute myocardial infarction (AMI) but the mechanism remains unclear. We performed a pooled analysis of 3,032 patients from the Primary Angioplasty in Myocardial Infarction (PAMI)-2, Stent-PAMI, and PAMI-No Surgery On Site trials to determine which clinical, hemodynamic, and angiographic characteristics in the elderly were associated with in-hospital death. There were 452 patients aged >/=75 years and 2,580 patients aged <75 years. Older patients had a lower number of risk factors for coronary artery disease but more comorbidities. Acute catheterization demonstrated more 3-vessel disease, higher left ventricular (LV) end-diastolic pressure, lower LV ejection fraction, and higher initial rates of Thrombolysis In Myocardial Infarction (TIMI) trial 2 or 3 flow. Elderly patients were equally likely to undergo percutaneous intervention but had a lower procedural success rate and lower rates of final TIMI 3 flow, and older patients were more likely to have post-AMI complications. In-hospital mortality was 10.2% and 1.8%, respectively (p = 0.001). Cardiac and noncardiac mortality was higher in elderly patients, and no significant differences in causes of death were identified. Multivariate analysis revealed that the strongest predictors of death were age >/=75 years, lower LV ejection fraction, lower final TIMI flow, higher Killip class, need for an intra-aortic balloon pump (IABP), and post-AMI stroke/transient ischemic attack, or significant arrhythmia. Despite avoiding thrombolysis, elderly patients remain at increased risk of bleeding, stroke, and other post-AMI complications, and death. Cardiac risk factor analysis and acute catheterization offer prognostic information but do not completely explain the mechanism of increased in-hospital mortality in the elderly.

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.