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Biomedical subjects

J S Hochman

Publications and source records attributed to J S Hochman.

At least 19 recordsLinked to original sources

Fatal cardiac rupture among patients treated with thrombolytic agents and adjunctive thrombin antagonists: observations from the Thrombolysis and Thrombin Inhibition in Myocardial Infarction 9 Study.

OBJECTIVES: The purpose of this study was to determine the incidence and demographic characteristics of patients experiencing cardiac rupture after thrombolytic and adjunctive anticoagulant therapy and to identify possible associations between the mechanism of thrombin inhibition (indirect, direct) and the intensity of systemic anticoagulation with its occurrence. BACKGROUND Cardiac rupture is responsible for nearly 15% of all in-hospital deaths among patients with myocardial infarction (MI) given thrombolytic agents. Little is known about specific patient- and treatment-related risk factors. METHODS Patients (n = 3,759) with MI participating in the Thrombolysis and Thrombin Inhibition in Myocardial Infarction 9A and B trials received intravenous thrombolytic therapy, aspirin and either heparin (5,000 U bolus, 1,000 to 1,300 U/h infusion) or hirudin (0.1 to 0.6 mg/kg bolus, 0.1 to 0.2 mg/kg/h infusion) for at least 96 h. A diagnosis of cardiac rupture was made clinically in patients with sudden electromechanical dissociation in the absence of preceding congestive heart failure, slowly progressive hemodynamic compromise or malignant ventricular arrhythmias. RESULTS A total of 65 rupture events (1.7%) were reported-all were fatal, and a majority occurred within 48 h of treatment Patients with cardiac rupture were older, of lower body weight and stature and more likely to be female than those without rupture (all p < 0.001). By multivariable analysis, age >70 years (odds ratio [OR] 3.77; 95% confidence interval [CI] 2.06, 6.91), female gender (OR 2.87; 95% CI 1.44, 5.73) and prior angina (OR 1.82; 95% CI 1.05, 3.16) were independently associated with cardiac rupture. Independent predictors of nonrupture death included age >70 years (OR 3.68; 95% CI 2.53, 5.35) and prior MI (OR 2.14; 95%, CI 1.45, 3.17). There was no association between the type of thrombin inhibition, the intensity of anticoagulation and cardiac rapture. CONCLUSIONS Cardiac rupture following thrombolytic therapy tends to occur in older patients and may explain the disproportionately high mortality rate among women in prior dinical trials. Unlike major hemorrhagic complications, there is no evidence that the intensity of anticoagulation associated with heparin or hirudin administration influences the occurrence of rupture.

Adult

SHould we emergently revascularize Occluded Coronaries for cardiogenic shocK: an international randomized trial of emergency PTCA/CABG-trial design. The SHOCK Trial Study Group.

BACKGROUND: Cardiogenic shock (CS) is the leading cause of death in patients hospitalized with acute myocardial infarction (MI). Nonrandomized studies suggest reduced mortality rate with revascularization. TRIAL DESIGN: The SHOCK trial is a multicenter, randomized, and unblinded study with a Registry for trial-eligible and ineligible nonrandomized patients. The trial is testing the hypothesis that a direct invasive strategy of emergency revascularization for patients with cardiogenic shock complicating acute MI will reduce 30-day all-cause mortality rate by 20 absolute percentage points compared with initial medical stabilization. Eligibility criteria include development of CS within 36 hours of an acute transmural MI as evidenced by ST elevation or new left bundle branch block MI; clinical criteria for CS with hemodynamic confirmation; absence of a mechanical, iatrogenic, or other cause of shock; and enrollment within 12 hours of CS diagnosis. Patients randomly assigned to emergency revascularization immediately undergo coronary angiography, with percutaneous transluminal coronary angioplasty or coronary artery bypass grafting depending on the coronary anatomy. Patients assigned to initial medical stabilization may undergo revascularization >/=54 hours after randomization. END POINTS: The primary end point is all-cause 30-day mortality after randomization. Secondary end points include death at trial termination, changes in left ventricular dimensions and function measured by echocardiography at randomization and 2 weeks later, and changes in quality of life and physical functioning from 2 weeks after discharge to 6 months after MI.

Angioplasty, Balloon, Coronary

The use of intraaortic balloon counterpulsation as an adjunct to reperfusion therapy in cardiogenic shock.

Modern coronary care unit interventions have not reduced the high mortality rate associated with cardiogenic shock due to acute myocardial infarction. Results with thrombolytic therapy have also been disappointing because of poor infarct artery patency rates in a low coronary flow state. Percutaneous transluminal coronary angioplasty appears to be a beneficial intervention, but the technique is not available at most hospitals. Intraaortic balloon counterpulsation provides temporary hemodynamic and clinical improvement in the majority of patients with cardiogenic shock. The use of intraaortic counterpulsation to augment patency rates with thrombolytic therapy or to stabilize patients for transfer to a hospital with angioplasty services appears to be a promising strategy for hospitals without an interventional cardiac catheterization laboratory.

Clinical Trials as Topic

Effects of prior aspirin and anti-ischemic therapy on outcome of patients with unstable angina. TIMI 7 Investigators. Thrombin Inhibition in Myocardial Ischemia.

Both aspirin and beta-adrenergic blocking drugs have been shown to reduce the risk of death or acute myocardial infarction (AMI) in patients with unstable angina, but their effect during chronic use on the presentation of acute coronary syndromes is less well defined. Calcium antagonists and oral nitrates are also widely prescribed for patients with coronary disease, but their effect on presentation of acute myocardial ischemia is unknown. We retrospectively examined the effects of prior aspirin and anti-ischemic medical therapy on clinical events in 410 patients hospitalized for unstable angina. Ischemic pain occurred at rest for a duration of 5 to 60 minutes. During hospitalization, 97% of patients received aspirin and all received the direct thrombin inhibitor bivalirudin for at least 72 hours. Despite being older and more likely to have risk factors for coronary disease and poor outcome, patients receiving aspirin before admission were less likely to present with non-Q-wave AMI (5% vs 14% in patients not on aspirin, p = 0.004). Prior beta blocker, calcium antagonist, or nitrate administration did not appear to modify presentation as unstable angina or non-Q-wave AMI. In a multivariate model, the combined incidence of death, AMI not present at enrollment, or recurrent angina was best predicted by age (adjusted odds ratio [95% confidence interval] 2.38 [1.14 to 3.98]) and presence of electrocardiographic changes with pain on presentation (adjusted odds ratio 2.83 [1.50 to 5.35]) but was not related to prior or in-hospital medical therapy. Thus, aspirin but not anti-ischemic therapy before hospitalization of patients with unstable angina was associated with a decreased incidence of non-Q-wave AMI on admission.

Adrenergic beta-Antagonists

Functional consequences of acute collagen degradation studied in crystalloid perfused rat hearts.

OBJECTIVES: The impact of acute collagen disruption by the disulfide donor, 5,5'-dithio-2-nitrobenzoic acid (DTNB) on ventricular properties was tested in rat hearts. METHODS: Collagen was degraded acutely in 13 isolated, isovolumically contracting rat hearts by perfusion with 1 mM DTNB added to Krebs-Henseleit solution for 1 hour followed by 2-hour perfusion with normal solution. Another 13 hearts were perfused with normal solution for 3 hours (Control). RESULTS: Collagen content was 3.5 +/- 0.5% of ventricular dry weight in control group compared with 2.1 +/- 0.4% in DTNB group (decrease by 40%, p < 0.01). Scanning electron micrographs revealed loss of the delicate collagen network surrounding muscle fibers in DTNB treated hearts. Developed pressure at a fixed volume decreased to 86 +/- 17% of the baseline value after 3-hour perfusion in the control group, whereas in DTNB treated hearts developed pressure fell to 68 +/- 13% (p < 0.01). End-diastolic pressure was set at 5 mmHg at the beginning of the experiment and rose to 15 +/- 8 mmHg in control and 30 +/- 13 mmHg (p < 0.01) in the treated hearts. Concomitantly, wet-to-dry weight ratio increased from 5.63 +/- 0.26 in control to 6.07 +/- 0.11 (p < 0.05) in the DTNB treated hearts. A separate set of experiments on isolated myocytes excluded the possibility of a direct effect of DTNB on myocyte contractile function. CONCLUSIONS: These data suggested that with 40% collagen disruption by DTNB there is a significant increase in tissue edema that results in a decrease in chamber capacitance; in addition, there is a significant decrease in systolic performance which reflects the combined effect of edema and loss of collagen.

Animals

Outcome and profile of women and men presenting with acute coronary syndromes: a report from TIMI IIIB. TIMI Investigators. Thrombolysis in Myocardial Infarction.

OBJECTIVES: Women and men enrolled in the Thrombolysis in Myocardial Infarction (TIMI) IIIB trial of unstable angina and non-Q wave myocardial infarction (MI) were evaluated to determine gender differences in characteristics and outcome. BACKGROUND: Coronary heart disease is the leading cause of death for women and men. However, the characteristics and outcome of women compared with men with unstable angina and non-Q wave MI have not been extensively studied. METHODS: The characteristics, outcomes and proportion of 497 women and 976 men with unstable angina and non-Q wave MI at the time of enrollment were compared. When these proportions were noted to be significantly different, we compared them with the 7,731-patient TIMI IIIB Registry, which represents the non-trial, screened population with these syndromes at these centers. RESULTS: For both coronary syndromes, women were older, were less frequently white, had a higher incidence of diabetes and hypertension and were receiving more cardiac medications. The 42-day rate of death and MI in TIMI IIIB was similar for women and men (7.4% vs. 7.5%). Coronary angiography revealed less severe coronary artery disease for women than for men, with absence of critical obstructions in 25% versus 16% and mean ejection fractions 62 +/- 12% versus 57 +/- 13% for women versus men (p < 0.01). Medical management failed in women as often as in men, and rates of cardiac catheterization and percutaneous transluminal coronary angioplasty or coronary artery bypass graft surgery were similar for women and men in the conservative strategy arm as well as in the invasive strategy arm. Women in the TIMI IIIB trial had proportionately more unstable angina than did men. The proportion of unstable angina and non-Q wave MI for women was similar in the trial and Registry. However, proportionately more men in the trial had non-Q wave MI than men in the Registry. CONCLUSIONS: 1) Women with each acute coronary syndrome are older than men and have more comorbidity. 2) The outcome with unstable angina and non-Q wave MI is related to severity of illness and not gender. 3) Mortality associated with revascularization for unstable angina and non-Q wave MI was similar for women and men. 4) The proportion of women and men enrolled with each acute coronary syndrome is different. These rates reflect both the prevalence of disease and selection bias owing to trial eligibility criteria and other identified factors.

Age Factors

Current spectrum of cardiogenic shock and effect of early revascularization on mortality. Results of an International Registry. SHOCK Registry Investigators.

BACKGROUND: Cardiogenic shock remains the leading cause of death of patients hospitalized with acute myocardial infarction (MI). This study was conducted to examine (1) the current spectrum of cardiogenic shock, (2) the proportion of patients who are potential candidates for a trial of early revascularization, and (3) the apparent impact of early revascularization on mortality. METHODS AND RESULTS: Nineteen participating centers in the United States and Belgium prospectively registered all patients diagnosed with cardiogenic shock. Two hundred fifty-one patients were registered. The mean age was 67.5 +/- 11.7 years, and 43% were women. Acute mitral regurgitation or ventricular septal rupture was the cause of shock in 8%. Concurrent conditions contributing to the development of shock were noted in 5%, and 2% had isolated right ventricular shock. Among the remaining 214 patients, nonspecific findings on the ECG associated with "nontransmural" MI were seen in 14%. The median time to shock diagnosis after MI was 8 hours. The overall in-hospital mortality was 66%. Patients clinically selected to undergo cardiac catheterization were significantly younger and had a lower mortality than those not selected (51% versus 85%, P < .0001) even if they were not revascularized (58%). Mortality for patients undergoing percutaneous transluminal coronary angioplasty (PTCA) was 60% (n = 55) and 19% (n = 16) for coronary artery bypass graft surgery (CABG). Sixty percent (n = 150) of registered patients were judged eligible for a trial of early revascularization. Trial-eligible patients were significantly younger (65.4 +/- 11.0 versus 70.6 +/- 11.9 years, P < .001), had an earlier median time to shock onset after MI (6.5 versus 17.5 hours, P = .003), and had lower mortality (62% versus 73%, P = .077) than ineligible patients. CONCLUSIONS: Patients diagnosed with cardiogenic shock complicating acute MI are a heterogeneous group. Those eligible for a trial of early revascularization tended to have lower mortality. Patients selected to undergo cardiac catheterization had lower mortality whether or not they were revascularized. Emergent PTCA and CABG are promising treatment modalities for cardiogenic shock, but biased case selection for treatment may confound the data. Whether PTCA and CABG reduce mortality and which patient subgroups benefit most remain to be determined in a randomized clinical trial.

Aged

Indications for immediate angiotensin-converting enzyme inhibition in patients with acute myocardial infarction.

When initiated a few days after myocardial infarction, angiotensin-converting enzyme inhibition exerts beneficial effects on survival and morbidity in patients with asymptomatic left ventricular systolic dysfunction or symptomatic heart failure. During the acute phase of a myocardial infarction, angiotensin-converting enzyme inhibition appears to be well tolerated, to prevent the development of heart failure in patients with asymptomatic left ventricular systolic dysfunction and to improve the hemodynamic and clinical variables of heart failure when present. Accordingly, early angiotensin-converting enzyme inhibition is clearly indicated in patients with acute myocardial infarction associated with asymptomatic left ventricular dysfunction or clinical evidence of heart failure. Angiotensin-converting enzyme inhibition may also be beneficial when thrombolytic agents fail to restore coronary patency in patients with acute myocardial infarction.

Angiotensin-Converting Enzyme Inhibitors

Interaction of ischaemia and encainide/flecainide treatment: a proposed mechanism for the increased mortality in CAST I.

OBJECTIVE: To determine whether an interaction between encainide or flecainide and intercurrent ischaemia could account for the observed increase in cardiac and sudden deaths in the study group in the Cardiac Arrhythmia Suppression Trial (CAST) I. DESIGN: CAST I was a randomised, double blind, placebo controlled study in which patients received the drug which suppressed at least 6 premature ventricular contractions per minute by 80% or episodes of non-sustained ventricular tachycardia by 90%. Arrhythmic sudden death or aborted sudden death were the study end points. Measured secondary end points included recurrent myocardial infarction, new or increasing angina pectoris, congestive heart failure, and syncope. The CAST I database was analysed to determine which of three end points occurred first--cardiac death or cardiac arrest, angina pectoris, or non-fatal recurrent infarction. They were regarded as mutually exclusive end points. The triad of cardiac or sudden arrhythmic death plus congestive heart failure and syncope was similarly analysed. RESULTS: It was assumed that recurrent non-fatal infarction and new or increasing angina pectoris were ischaemic in origin. The sum of these non-fatal ischaemic end points and sudden death were nearly identical in the placebo group (N = 129) and the treatment group (N = 131). The one year event rate in each group was 21%. However, the treatment group had a much greater fatality rate (55 v 17; P < 0.0001) than the placebo group. The same relation was found when the data were examined on the basis of drug exposure rather than intention to treat. The temporal and circadian events were similar in each group and were consistent with an ischaemic pattern. No such patterns emerged from analysis of the presumed non-ischaemic end points of congestive heart failure and syncope. CONCLUSIONS: These data suggest that the interaction between active ischaemia and treatment with encainide or flecainide may have been responsible for the increased mortality seen in the treatment group in CAST I. This conversion of a non-fatal to a fatal event emphasises the need for future antiarrhythmic drugs to be screened in ischaemic models.

Angina Pectoris

Prognostic significance of left ventricular aneurysm in the Cardiac Arrhythmia Suppression Trial (CAST) population.

Left ventricular aneurysm has been associated with increased mortality rates. The Cardiac Arrhythmia Suppression Trial (CAST) database was used prospectively to assess (1) the prognostic significance of left ventricular (LV) aneurysm after myocardial infarction on mortality rates and (2) the relation of LV aneurysm to ventricular arrhythmias and their suppressibility. All patients in the CAST study were enrolled after myocardial infarction. They had > or = 6 ventricular premature depolarizations (VPDs) per hour and ejection fraction < or = 55%; they were enrolled in the study an average of 96 days after the index myocardial infarction. Of 2494 patients with wall motion data, 164 had LV aneurysm, 600 had only dyskinesis, 913 had only akinesis, and 817 had none of these. Radionuclide scan was used in 39%, two-dimensional echocardiography in 30%, and LV angiogram in 31%. Baseline VPDs and nonsustained ventricular tachycardia were similar in all groups. LV aneurysm patients were more frequently eliminated during open-label titration. The incidence of sustained VT during follow-up was only 2.8% for aneurysm patients, a rate that was similar to the other groups. Patients with LV aneurysm had significantly lower survival rates (82% vs 91%) at 16 months after study entry than those without these wall motion abnormalities (p < 0.005). When survival rates were adjusted for ejection fraction there was still a moderately large hazard ratio (1.34) of LV aneurysm that was not statistically significant (p = 0.18). We conclude that (1) the presence of LV aneurysm does not independently worsen prognosis, and (2) older concepts of LV aneurysm and ventricular arrhythmias must be reevaluated.

Arrhythmias, Cardiac

Effects of thrombolytic therapy administered 6 to 24 hours after myocardial infarction on the signal-averaged ECG. Results of a multicenter randomized trial. LATE Ancillary Study Investigators. Late Assessment of Thrombolytic Efficacy.

BACKGROUND: Thrombolytic therapy reduces mortality after acute myocardial infarction, even when treatment is initiated relatively late after onset of symptoms. The mechanism underlying this survival benefit is incompletely understood. METHODS AND RESULTS: In a prospectively designed ancillary study of a randomized, placebo-controlled trial of late thrombolytic therapy (LATE), the signal-averaged (SA) ECG was recorded before hospital discharge in an effort to assess the effect of thrombolytic therapy on arrhythmia substrate. Three hundred ten patients were enrolled at 23 participating sites; 160 patients received placebo, and 150 patients received recombinant tissue-type plasminogen activator (rTPA) therapy 6 to 24 hours after onset of symptoms. Compared with placebo, rTPA tended to reduce the frequency of SAECG abnormality (filtered QRS duration > 120 milliseconds) by 37% (95% CI, -64%, +6%; P = .087) and the filtered QRS duration (105.7 +/- 13.8 versus 108.8 +/- 14.6 milliseconds, P = .05). In the prespecified subgroup of 185 patients with ST elevation on the qualifying ECG, rTPA resulted in a 52% reduction (95% CI, 4% to 77%, P = .011) of SAECG abnormality and a shorter filtered QRS duration (105.7 +/- 10.9 versus 110.7 +/- 15.9 milliseconds, P = .01). No benefit was seen in patients without ST elevation on ECG. CONCLUSIONS: Late thrombolytic therapy produced a more stable electrical substrate, which probably represents an important mechanism of mortality benefit.

Double-Blind Method

Effect of atenolol on myocardial infarct expansion in a nonreperfused rat model.

Acute myocardial infarct expansion is associated with a poor prognosis. This study was performed to assess potential beneficial effects of beta-blockers on inhibiting expansion. A pilot study showed that atenolol (10 mg/kg) achieved sustained beta-blockade in rats. In the main study, following left coronary ligation, 36 rats received atenolol and 18 rats received placebo daily for 7 days. Infarct size was similar in treated and control rats (25 +/- 13% versus 28 +/- 11%). Expansion grades and a quantitative index of expansion were similar for both groups. Infarct size and expansion index were significantly related, but linear regression lines were similar for treated and control rats. We conclude that atenolol has no significant effect on infarct expansion in this nonreperfused rat model.

Adrenergic beta-Antagonists

The distribution of atherosclerotic lesions in the coronary arterial tree: relation to cardiac risk factors.

Although it is often stated that proximal atherosclerotic coronary artery disease occurs more frequently than distal disease, several autopsy studies have disputed this. To examine the prevalence of proximal vs mid and distal disease and its relationship with cardiac risk factors, we studied more than 14,000 sections from 102 hearts with coronary artery disease at autopsy. After postmortem angiography, the coronary arteries were removed, divided into proximal, mid, and distal thirds, sectioned at 2.5 mm intervals, and graded for percentage reduction in cross-sectional area by atherosclerosis. Of 252 vessels in 84 patients with greater than or equal to 75% stenosis, 166 (66%) has proximal disease vs 107 (42%) with mid disease and 40 (16%) with distal disease (p less than 0.001). No patient had a mid or distal stenosis greater than 75% without proximal disease. When atherosclerosis of any severity was assessed, proximal atherosclerotic lesions were long and diffuse, whereas distal lesions were more often short and discrete. Proximal circumflex lesions were shorter in length than those in the right or left anterior descending coronary arteries. The prevalence of proximal, mid, and distal stenoses in 25 diabetic patients was similar to that in nondiabetic persons (53%, 47%, and 17%, p greater than 0.3). Similarly, hypertension, smoking, and obesity were not associated with an increase in prevalence of distal disease. Patients with distal stenoses were younger than patients without (mean age, 64 +/- 13 vs 73 +/- 10 years, p less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Aged

Limitation of myocardial infarct expansion by reperfusion independent of myocardial salvage.

Very early reperfusion after coronary occlusion can reduce infarct size and preserve left ventricular function. Whether later reperfusion is of benefit is unclear. We studied the effect of very early reperfusion with myocardial salvage and "late" reperfusion without myocardial salvage on infarct expansion and aneurysm formation. Sixty-eight rats underwent left coronary artery ligation and were randomized to 30 min reperfusion, 2 hr reperfusion, or permanent coronary artery ligation. The animals were killed and the hearts examined at 2 weeks. Thirty minute reperfusion reduced infarct size, extent of transmurality, and infarct expansion. Two hour reperfusion reduced neither infarct size nor transmurality but inhibited infarct expansion. The results of this study in the rat preparation suggest a beneficial effect of "late" reperfusion on infarct expansion independent of myocardial salvage. If these results are confirmed in human beings, the period after myocardial infarction during which a patient can be considered for thrombolytic therapy or reperfusion by percutaneous transluminal coronary angioplasty could be greatly prolonged.

Animals

Effect of exercise on acute myocardial infarction in rats.

Infarct expansion, the time-related thinning and dilation of an acute transmural infarct, leads to aneurysm formation and cardiac rupture in humans. In this study, the effect of exercise on acute infarct expansion early after myocardial infarction was examined in 129 rats. Ninety rats were exercised on a treadmill for 1.5 hours daily for 1 week beginning on the day of coronary artery ligation; the remaining 39 rats remained in their cages. There was no effect on the prevalence or extent of expansion; specifically, infarct wall thickness, left ventricular diameter and expansion grade (0 to 4+) were similar in the exercise and control rats. There was no difference in infarct size or the number of animals with aneurysmal shape changes in the exercise and control groups. There was no significant difference between the two groups in the histologic finding of intramural hemorrhage, a feature that has been associated with cardiac rupture, and no complete rupture was seen. However, there was a nonsignificant trend toward higher mortality in the exercised group. Thus, the findings of this study suggest that moderate exercise early after myocardial infarction produces no significant detrimental effect on infarct size or left ventricular topography in the rat model.

Animals