J W Kennedy

Three-year outcome after balloon aortic valvuloplasty: Insights into prognosis of valvular aortic stenosis

BackgroundTo identify predictors of long-term outcome after balloon aortic valvuloplasty, we analyzed data on 674 adults (mean age, 78±9 years; 56% were women) undergoing this procedure at 24 clinical centers who had a mean initial increase in aortic valve area of 0.3 cm2. Methods and ResultsBaseline data included clinical, echocardiographic, and catheterization variables. Follow-up data included mortality, cause of death, rehospitalization, 6-month echocardiography, and functional status. Kaplan-Meier curves and log-rank tests were used to evaluate survival in subgroups. Multivariate Cox regression models were used to identify independent predictors of survival. Overall survival was 55% at 1 year, 35% at 2 years, and 23% at 3 years, with the majority of deaths (70%) classified as cardiac by an independent review committee. Rehospitalization was common (64%), although 61% of survivors at 2 years reported improved symptoms. Echocardiography at 6 months (n= 115) showed restenosis from the postprocedural valve area of 0.78±0.31 cm2 to 0.65±0.25 cm2 (P < .0001). With stepwise multivariate analysis, sequentially adding clinical, echocardiographic, and catheterization variables, the overall model identified independent predictors of survival as baseline functional status, baseline cardiac output, renal function, cachexia, female gender, left ventricular systolic function, and mitral regurgitation. Baseline and postprocedural variables were examined to identify which subgroup of patients has the best outcome after aortic valvuloplasty. A “lower-risk” subgroup (28% of the study population), defined by normal left ventricular systolic function and mild clinical functional limitation, had a 3-year survival of 36% compared with 17% in the remainder of the study group. ConclusionsLong-term survival after balloon aortic valvuloplasty is poor with 1- and 3-year survival rates of 55% and 23%, respectively. Although survivors report fewer symptoms, early restenosis and recurrent hospitalization are common.

The Western Washington Intravenous Streptokinase in Acute Myocardial Infarction Randomized Trial.

Three hundred sixty-eight patients were randomly assigned to receive intravenous streptokinase (IVSK) (n = 191) or standard therapy (n = 177) to determine the efficacy of IVSK in the treatment of acute myocardial infarction. The mean time to treatment was 3.5 hr. At 14 days there were 12 deaths in the treatment group (6.3%) and 17 deaths in the control group (9.6%) (p = .23). Early mortality was related to infarct location. Fourteen day mortality for anterior infarctions was 10.4% for treatment with IVSK and 22.4% for control patients (p = .06) and was similar for IVSK-treated patients with inferior infarctions, 4.0% vs 1.8% (p = .32). For those randomized under 3 hr, 14 day mortality tends to be lower in treated patients, 5.2% vs 11.5% (p = .11). There was significant improvement in long-term survival for patients with anterior infarction; 2 year survival was 81% for IVSK-treated patients and 65% for control patients (p = .05). There was no improvement in survival for patients with inferior myocardial infarction (p = .27). We conclude that patients with anterior myocardial infarction have improved survival when treated within the first 6 hr of symptoms. Patients with inferior infarction do not appear to have improved survival with thrombolytic therapy. Some of this improvement in survival in patients with anterior infarction may be due to a higher frequency of revascularization procedures in the treatment group.

Global and regional left ventricular function and tomographic radionuclide perfusion: the Western Washington Intracoronary Streptokinase In Myocardial Infarction Trial.

The Western Washington Intracoronary Streptokinase In Myocardial Infarction Trial enrolled 250 patients with acute myocardial infarction. After the coronary angiographic diagnosis of thrombosis, patients were randomly assigned to receive either conventional therapy with heparin or intracoronary streptokinase followed by heparin. Of the 232 patients who survived at least 60 days, 207 (89%) underwent radionuclide ventriculographic determination of global and regional ejection fraction at a single institution at 62 +/- 35 days after infarction. In the first 100 patients, infarct size was also determined by quantitative single-photon emission tomographic imaging with thallium-201 (201Tl) and expressed as a percentage of the left ventricle with a perfusion defect. Overall, global ejection fraction did not differ between patients treated with streptokinase (45.9 +/- 13.9%; n = 115) and control patients (46.1 +/- 14.4%; n = 92, p = NS). Similarly, the regional posterolateral, inferior, and anteroseptal ejection fraction did not differ between the two groups. Infarct size as measured by 201Tl tomography was 19.4 +/- 12.8% (n = 52) of the left ventricle for the streptokinase group and 19.6 +/- 11.8% (n = 48; p = NS) for the control group. When patients were compared within groups by electrocardiographic location of infarction, time to treatment, or the presence or absence of vessel opening, there were no significant differences between streptokinase and control patients. Statistical inclusion of the 18 patients who died early and were unavailable for study also failed to modify the results, except for a possible reduction in inferior infarct size as measured by 201Tl tomography.(ABSTRACT TRUNCATED AT 250 WORDS)

Serial exercise radionuclide angiography. Validation of count-derived changes in cardiac output and quantitation of maximal exercise ventricular volume change after nitroglycerin and propranolol in normal men.

R–wave–synchronous radionuclide angiography provides time–activity curve information that is assumed to be proportional to ventricular volumes. We performed serial 2-minute time–activity curves and simultaneous Fick cardiac outputs before and during graded, maximal, supine exercise in nine normal subjects; each subject exercised without drug intervention, after nitroglycerin and after intravenous propranolol. Imaging was performed using an R–wave–synchronized gamma camera–computer system, a high–sensitivity collimator and autologous 99mTc–labeled red blood cells. Fick cardiac output was determined from pulmonary and radial artery blood samples and oxygen consumption. Changes in count–derived cardiac output, expressed as percent change from baseline, closely paralleled changes in Fick output at all levels of exercise for nondrug and nitroglycerin studies. After propranolol, agreement was maintained between both methods for low–tomoderate levels of exercise. Changes in count–defined end–diastolic volume, end–systolic volume and stroke volume agreed well with simultaneous heart rate, wedge pressure and Fick measurements and were in accord with known hemodynamic effects of exercise, nitroglycerin and propranolol. We conclude that radionuclide count data accurately reflect true hemodynamic change as determined by the Fick technique and may aid in defining the mechanisms of ventricular dysfunction in coronary and valvular heart disease, thereby providing a better understanding of the effects of interventions in these disorders.

Risk stratification for 1 year survival based on characteristics identified in the early hours of acute myocardial infarction: the Western Washington Intracoronary Streptokinase Trial

We evaluated the relationship between baseline factors defined at 4.6 +/- 2.1 hr after onset of acute myocardial infarction and 1 year survival in 245 patients entered in the Western Washington Intracoronary Streptokinase Trial. Univariate statistics identified a significant relationship between 10 of these factors and survival. Multivariate analysis identified three factors as being most closely related to survival: (1) left ventricular ejection fraction (LVEF) (p less than .0001), (2) treatment with streptokinase (p = .03), and (3) location of infarction (p = .04). Mathematic models based on this analysis and applied to our patients identified high- and low-risk subgroups for 1 year mortality. Patients receiving standard, not interventional, therapy with anterior infarction and an LVEF of 50% or less and those with inferior infarction and an LVEF of 39% or less comprised the high-risk group. For patients receiving standard therapy, 1 year mortality was 41% in the high-risk group and 4% in the low-risk group. The models illustrated the magnitude of benefit of streptokinase treatment and achievement of complete reperfusion for those at low and high risk. We conclude that LVEF determined in the first hours of acute myocardial infarction is the most important of all baseline factors for prediction of 1 year survival. Mathematic models based on left ventricular function measured as ejection fraction are useful for risk stratification in this setting.

Intravenous streptokinase for acute myocardial infarction. Effects on global and regional systolic function.

The Western Washington Intravenous Streptokinase Trial randomized 368 patients with acute myocardial infarction to receive either intravenous streptokinase or standard therapy. The ventriculograms and coronary angiograms obtained in 170 patients 10.4 +/- 7.4 days after infarction were analyzed to evaluate the effects of thrombolytic therapy on global and regional systolic function. Streptokinase treatment resulted in a higher patency rate of the infarct-related artery (68.5%) than did standard therapy (44.8%) (p = 0.003). Ejection fraction was higher in streptokinase-treated patients (54% vs. 51%, p = 0.056), and the difference was most marked in patients with anterior myocardial infarction (53% vs. 44%, p = 0.03). Regional wall motion was measured by the centerline method and expressed in mean +/- SD motion in 52 normal subjects. There was a trend toward better function of the infarct zone in streptokinase-treated patients (SD, -2.48 vs. -2.70, p = 0.24). Additionally, streptokinase-treated patients had significantly better wall motion of noninfarct areas (SD, 0.36 vs. -0.08, p = 0.02). Treatment effects on function of noninfarct regions were most apparent in the subset of patients with multivessel disease. Thus, intravenous streptokinase preserves left ventricular function in patients with acute myocardial infarction. This benefit includes favorable effects on the function of regions remote from the site of infarction.

Early mortality of acute myocardial infarction in patients with and without prior coronary revascularization surgery. A Coronary Artery Surgery Study Registry Study.

BackgroundThe Coronary Artery Surgery Study (CASS) Registry is used to evaluate the effect of various baseline clinical and angiographic factors on mortality after acute out-of-hospital myocardial infarction (MI) in patients with and without prior coronary bypass surgery. Methods and ResultsAmong the CASS Registry patients, there were 985 medical and 369 surgical patients who had an MI out of the hospital within 3 years after enrollment. In the medical group, 20% died before hospitalization. Medical patients with baseline three-vessel disease or left ventricular (LV) dysfunction were at high risk of immediate death. For medical patients who were hospitalized with MI, mortality was higher for older patients and those with severe angina as well as for those with extensive disease and LV dysfunction. The total 30-day mortality for medical patients was 36%. In the surgical group, 12% died before hospitalization. Surgical patients with LV dysfunction or prior MI were at highest risk of immediate death. For surgical patients hospitalized with MI, mortality was significantly increased only for patients with baseline LV dysfunction. Mortality was not significantly higher for surgical patients with multivessel disease. The total 30-day mortality for surgical patients was 21%. The prior use of aspirin or β-blockers was not associated with reduced mortality from subsequent MI for either medical or surgical patients. Although the prevalence of cigarette smoking was high among patients who had an MI, cigarette smoking did not alter the infarct-related mortality rate. ConclusionsThe surgical group had lower mortality rates than the medical group both immediately (p=0.001), after hospitalization (p<0.0001), and at 30 days (p<0.0001).