Charles Hansen

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.

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.

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.

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

OBJECTIVESnThe 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.nnnBACKGROUNDnInfarct-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.nnnMETHODSnWe 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.nnnRESULTSnPatients 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.nnnCONCLUSIONSnInfarct-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.

Very Late Stent Thrombosis After Primary Percutaneous Coronary Intervention With Bare-Metal and Drug-Eluting Stents for ST-Segment Elevation Myocardial Infarction: A 15-Year Single-Center Experience

OBJECTIVESnThe purpose of this study was to assess the frequency of very late stent thrombosis (VLST) after stenting with bare-metal stents (BMS) and drug-eluting stents (DES) for ST-segment elevation myocardial infarction (STEMI).nnnBACKGROUNDnStent thrombosis occurs more frequently after stenting for STEMI than after elective stenting, but there are little data regarding VLST.nnnMETHODSnConsecutive patients (n = 1,463) who underwent stenting for STEMI were prospectively enrolled in our database. BMS were implanted exclusively from 1995 to 2002, and DES and BMS were implanted from 2003 to 2009. Follow-up was obtained at 1 to 15 years.nnnRESULTSnBMS patients (n = 1,095) were older and had more shock, whereas DES patients (n = 368) had more diabetes and smaller vessels. Stent thrombosis occurred in 107 patients, of which 42 were VLST (>1 year). Stent thrombosis continued to increase to at least 11 years with BMS and to at least 4.5 years with DES. Stent thrombosis rates with BMS versus DES were similar at 1 year (5.1% and 4.0%, respectively) but increased more with DES after the first year (1.9%/year vs. 0.6%/year, respectively). Landmark analysis (>1 year) found DES had a higher frequency of VLST (p < 0.001) and reinfarction (p = 0.003). DES was the only significant independent predictor of VLST (hazard ratio: 3.79, 95% confidence interval: 1.64 to 8.79, p = 0.002).nnnCONCLUSIONSnVLST after primary PCI for STEMI occurs with relatively high frequency to at least 11 years with BMS and to at least 4.5 years with DES. Very late stent thrombosis and reinfarction (>1 year) were more frequent with DES. New strategies are needed to manage this problem.

Racial Differences in Patients’ Perceptions of Debilitated Health States †

OBJECTIVE: To determine health utility scores for specific debilitated health states and to identify whether race or other demographic differences predict significant variation in these utility scores.DESIGN: Utility analysis.SETTING: A community hospital general internal medicine clinic, a private internal medicine practice, and a private pulmonary medicine practice.PARTICIPANTS: Sixty-four consecutive patients aged 50 to 75 years awaiting appointments. In order to participate, patients at the pulmonary clinic had to meet prespecified criteria of breathing impairment.MEASUREMENTS: Individuals’ strength of preference concerning specific states of limited physical function as measured by the standard gamble technique.MAIN RESULTS: Mean utility scores used to quantitate limitations in physical function were extremely low. Using a scale for which 0 represented death and 1.0 represented normal health, limitation in activities of daily living was rated 0.19 (95% confidence interval [CI] 0.13, 0.25), tolerance of only bed-to-chair ambulation 0.17 (95% CI 0.11, 0.23), and permanent nursing home placement 0.16 (95% CI 0.10, 0.22). Bivariate analysis identified female gender and African-American race as predictors of higher utility scores (p ≦ .05). In multiple regression analysis, only race remained statistically significant (p ≦ .02 for all three outcome variables).CONCLUSION: Comparisons of African-American values with those of whites concerning defined states of debility demonstrate greater than threefold increases in utility scores. This finding suggests that racial differences need to be taken into account when studying the effects of medical interventions on quality of life.

Predictors of early, late, and very late stent thrombosis after primary percutaneous coronary intervention with bare-metal and drug-eluting stents for ST-segment elevation myocardial infarction.

OBJECTIVESnThe purpose of this study was to evaluate the frequency and predictors of stent thrombosis (ST) after stenting for ST-segment elevation myocardial infarction (STEMI).nnnBACKGROUNDnStent thrombosis remains a major concern with STEMI patients treated with primary percutaneous coronary intervention.nnnMETHODSnConsecutive patients (N = 1,640) undergoing stenting for STEMI were prospectively enrolled in our database and followed for 1 to 15 years. Bare-metal stents were implanted from 1995 to 2002, and drug-eluting and bare-metal stents were implanted from 2003 to 2009. Stent thrombosis was defined as definite or probable.nnnRESULTSnOur population had a high risk profile, including a high incidence of Killip class III to IV (11.5%) and STEMI due to ST (10.2%). Stent thrombosis occurred in 124 patients, including 42 with early ST (0 to 30 days), 35 with late ST (31 days to 1 year), and 47 with very late ST (>1 year). The frequency of ST was 2.7% at 30 days, 5.2% at 1 year, and 8.3% at 5 years. Independent predictors of early or late ST were STEMI due to ST (hazard ratio [HR]: 4.38, 95% confidence interval [CI]: 2.27 to 8.45), small stent size (HR: 2.44, 95% CI: 1.49 to 4.00), Killip class III to IV (HR: 2.39, 95% CI: 1.30 to 4.40), and reperfusion time ≤2 h (HR: 2.09, 95% CI: 1.03 to 4.24). Drug-eluting stent was the only independent predictor of very late ST (HR: 3.73, 95% CI: 1.81 to 7.88).nnnCONCLUSIONSnStent thrombosis after primary percutaneous coronary intervention is relatively frequent and continues to increase out to 5 years. New strategies are needed to prevent ST in STEMI patients, and targeted therapies are needed in patients identified at highest risk.

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)

Poor long-term patient and graft survival after primary percutaneous coronary intervention for acute myocardial infarction due to saphenous vein graft occlusion†

Primary percutaneous coronary intervention (PCI) for ST segment elevation myocardial infarction (STEMI) due to saphenous vein graft (SVG) occlusion has been associated with poor procedural results and poor short‐term outcomes, but long‐term graft patency and patient survival have not been evaluated. Consecutive patients (n = 2,240) with STEMI treated with primary PCI from 1984 to 2003 were followed for 6.6 years (median). Follow‐up angiography was obtained in 80% of hospital survivors following primary PCI for SVG occlusion at 2.3 years (median). Patients with primary PCI for SVG occlusion (n = 57) vs. native artery occlusion had more prior MI, advanced Killip class, and three‐vessel coronary disease and lower acute ejection fraction (EF). Patients with SVG occlusion had lower rates of TIMI 3 flow post‐PCI (80.7% vs. 93.6%; P = 0.0001), higher in‐hospital mortality (21.1% vs. 8.0%; P = 0.0004), and lower follow‐up EF (49.3% vs. 54.7%; P = 0.055). Culprit SVGs were patent in 64% of patients at 1 year and 56% at 5 years. Late survival was strikingly worse in patients with primary PCI for SVG occlusion vs. native vessel occlusion (49% vs. 76% at 10 years), and SVG occlusion was the second strongest predictor of late cardiac mortality by multivariate analysis (HR = 2.11; 95% CI = 1.38–3.23; P = 0.0006). Patients with STEMI due to SVG occlusion treated with primary PCI have poor acute procedural results, frequent late reocclusion, and very high late mortality. The introduction of new adjunctive therapies (distal protection, thrombectomy, and drug‐eluting stents) may improve short‐term outcomes, but improved long‐term outcomes may require new and more durable revascularization strategies.