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Biomedical subjects

P T O'Gara

Publications and source records attributed to P T O'Gara.

At least 19 recordsLinked to original sources
PubMed2001

Comparison of two aspirin doses on ischemic stroke in post-myocardial infarction patients in the warfarin (Coumadin) Aspirin Reinfarction Study (CARS).

The Coumadin Aspirin Reinfarction Study demonstrated that combination treatment with fixed dose warfarin (1 or 3 mg) + aspirin 80 mg was not superior to aspirin 160 mg alone after myocardial infarction for reducing nonfatal reinfarction, nonfatal stroke, and cardiovascular death. In this analysis, we examined the importance of aspirin dose in the protection against the secondary end point of ischemic stroke. The comparison arms for this analysis were warfarin 1 mg + aspirin 80 mg versus aspirin 160 mg. In the Coumadin Aspirin Reinfarction Study, 2,028 patients were randomized to aspirin 80 mg plus warfarin 1 mg, and 3,393 were randomized to aspirin 160 mg alone. A predictive model for ischemic stroke was developed using the Cox proportional-hazards model. A reduced Cox proportional-hazards model was developed to test for the effect of aspirin dose on ischemic stroke in predefined subgroups. The incidence of ischemic stroke was lower in patients treated with aspirin 160 mg than in patients treated with aspirin 80 mg + warfarin 1 mg (0.6% vs 1.1%; p = 0.0534). Age, previous stroke or transient ischemic attack, and aspirin dose were independent predictors of ischemic stroke. In addition, the highest risk patients, those with Q-wave myocardial infarction and male patients, appeared to receive greater benefit from aspirin 160 mg than from aspirin 80 mg + warfarin 1 mg. The results of this secondary analysis suggest that aspirin 160 mg is more effective than aspirin 80 mg + warfarin 1 mg in preventing ischemic stroke in post-myocardial infarction patients.

Aged↗
PubMed2000

Lack of compensatory enlargement at sites of coronary vasospasm: identification by ultrasound and successful treatment with stenting.

The case of a young man with spontaneous vasospasm at two sites in his left anterior descending coronary artery is described. Intravascular ultrasound demonstrated mild eccentric atherosclerosis with smaller total artery cross-sectional area (defined as the external elastic membrane) compared with reference segments. Impaired compensatory enlargement (remodeling) in response to mild atherosclerosis may derive from one or more biologic mechanisms that are also responsible for vasospasm. This characteristic is easily identified by intravascular ultrasound. In this case, coronary stenting of the vasospastic sites led to excellent long-term control of symptoms more than 1 year after intervention.

Adult↗
PubMed1997

Gender differences in presentation, management, and cardiac event-free survival in patients with syncope.

In a MEDLINE search of published English studies (1966 to 1996), no prior study was identified that examined gender-based differences in the management and prognosis of patients admitted with syncope. We studied 109 consecutive patients (48 women) admitted with syncope at the Massachusetts General Hospital (1989 to 1990). All patients underwent Holter monitoring, signal-averaged electrocardiography, and echocardiography according to study protocol. Follow-up was 100% complete (10 +/- 4 months). Women were older (74 +/- 2 vs 66 +/- 2 years, p <0.01) and less likely to have premonitory symptoms when compared with men (46% vs 66%, p <0.05). A greater proportion of men had left ventricular ejection fractions of <0.40 (18% vs 0%, p <0.01), abnormal signal-averaged electrocardiograms (28% vs 8%, p <0.01), and a cardiac cause for syncope (49% vs 25%, p <0.01). Although referral for diagnostic electrophysiologic testing was >3 times as frequent for men compared with women (20% of men vs 6% of women, p <0.05), this difference was not significant after adjustment for age, ventricular arrhythmia, and referral for coronary angiography. During follow-up, 21% of men versus 6% of women (p <0.05) had cardiac events (recurrent syncope, myocardial infarction, or sudden death). Cardiac event-free survival rates were worse for men (p = 0.045). Thus, we have identified gender-based differences in the clinical presentation of syncope for hospital admission. Left ventricular dysfunction and an abnormal signal-averaged electrocardiogram occur more frequently in men. Men are more likely to have cardiac syncope and worse cardiac event-free survival when compared with women.

Aged↗
PubMed1996

Efficacy and safety of procainamide in preventing arrhythmias after coronary artery bypass surgery.

Arrhythmias are common after cardiac surgery and are associated with hemodynamic compromise, stroke, and prolonged hospitalization. Beta blockers prevent atrial fibrillation postoperatively, but there are few data regarding the prophylactic use of type 1 antiarrhythmic agents or the prevention of ventricular arrhythmias. Accordingly, we performed a randomized, double-blind, placebo-controlled study of the effects of oral procainamide on 100 patients undergoing elective coronary artery bypass surgery. Procainamide was received for 4 days; the dosage was adjusted for body weight. Patients receiving procainamide had a significant reduction in atrial fibrillation (16 vs 29 patient-days, p < 0.05) and ventricular tachycardia (2% vs 20%, p < 0.01). However, the incidence of atrial fibrillation was not significantly reduced (38% vas 26%). In the group achieving therapeutic serum procainamide levels, there was reduction in all measured postoperative arrhythmias. No serious cardiac or noncardiac adverse events were noted during procainamide therapy, although there was a significant increase in the incidence of nausea. We conclude that procainamide reduces arrhythmias in the early postoperative period after coronary artery bypass surgery, most prominently in patients who achieve therapeutic serum levels. This was associated with no serious cardiac adverse reactions.

Administration, Oral↗
PubMed1996

Care of acute myocardial infarction by noninvasive and invasive cardiologists: procedure use, cost and outcome.

OBJECTIVES: This study sought to determine how noninvasive and invasive cardiologists may differ in the hospital care of patients with acute myocardial infarction. BACKGROUND: Scant information exists regarding the effect of noninvasive and invasive cardiology subspecialization on invasive cardiac procedural use, cost and outcome in the care of patients with acute myocardial infarction. METHODS: This study analyzed a prospective cohort of 292 patients admitted to an urban tertiary care hospital from the emergency room under the care of noninvasive or invasive cardiologists. Clinical characteristics; hospital course, including management, utilization of diagnostic coronary angiography and percutaneous transluminal coronary angioplasty; direct hospital costs; length of hospital stay; and post-hospital discharge follow-up data were collected by a prospective data base instrument. RESULTS: Despite similar clinical characteristics, extent and severity of coronary artery disease and utilization of diagnostic coronary angiography in the two groups of patients, those under the care of an invasive cardiologist were significantly more likely to undergo coronary angioplasty than those under the care of a noninvasive cardiologist. The direct hospital costs and length of stay of the noninvasive and invasive group patients who underwent coronary angioplasty were similar, although overall the direct hospital costs and length of stay were higher for the invasive than for the noninvasive group patients. CONCLUSIONS: Noninvasive and invasive cardiologists differ in their rate of utilization of coronary angioplasty in similar patients with acute myocardial infarction.

Aged↗
PubMed1996

Geriatric patients with acute myocardial infarction: Cardiac risk factor profiles, presentation, thrombolysis, coronary interventions, and prognosis.

Elderly patients have a higher mortality after acute myocardial infarction (MI) yet are treated less aggressively than younger patients. To determine (l) the risk-factor profiles, (2) presentation, (3) management, and (4) hospital outcomes for the elderly (> or = 75 years) compared with middle aged (66 to 74 years) and younger (< or = 65 years) patients in the 1990s, we studied 561 consecutive patients with acute MI. Compared with younger patients, the elderly more frequently had congestive heart failure (40 percent vs 14 percent; p < 0.00001) and non-Q wave infarctions (76 percent vs 56 percent; p < 0.005), received thrombolysis (9 percent vs 34 percent; p < 0.0001), and underwent catheterization (35 percent vs 73 percent; p < 0.00001), percutaneous transluminal coronary angioplasty (9 percent vs 31 percent; p < 0.0002), and coronary artery bypass grafting (5 percent vs 15 percent; p < 0.03) less frequently. Those who did not receive thrombolysis all had contraindications. Mortality was higher in the elderly (19 percent vs 5 percent; p < 0.004), especially among those who did not receive thrombolysis (20 percent vs 7 percent; p < 0.03). Multivariate predictors of mortality included age, and congestive heart failure. In addition, when clinical course and management variables were considered, use of the intraaortic balloon pump was a predictor of mortality, whereas undergoing coronary angiography was a negative predictor (relative risk, 0.3; 95 percent confidence intervals, 0.1 to 0.6).

Adult↗
PubMed1995

Torsade de pointes caused by high-dose intravenous haloperidol in cardiac patients.

Intravenous haloperidol is the agent of choice for controlling severe agitated delirium in seriously ill cardiac patients in many institutions. Prior reports have proposed that high-dose intravenous haloperidol may be without untoward effects in these patients. Recently, however, a few reports of significant QTc prolongation and torsade de pointes as complications of high-dose intravenous haloperidol therapy have appeared. The present report describes three patients with definite haloperidol-induced QTc prolongation and torsade. In each case, QTc prolongation preceded the arrhythmia and disappeared following the discontinuation of haloperidol. Neither electrolyte imbalance, therapy with other cardiac drugs, bradycardia, ischemia, left ventricular dysfunction, nor other known cause of torsade was present in these patients. It is hypothesized that QTc prolongation and torsade likely are idiosyncratic, unpredictable reactions to high-dose haloperidol in select patients. Careful serial electrocardiographic monitoring and prompt discontinuation of the drug should suffice to prevent this relatively uncommon, life-threatening complication of high-dose intravenous haloperidol.

Aged↗
PubMed1995

Intramural mechanics in hypertrophic cardiomyopathy: functional mapping with strain-rate MR imaging.

PURPOSE: To characterize systolic and diastolic intramural mechanics in hypertrophic cardiomyopathy (HCM) with a new metric of contractile activity. MATERIALS AND METHODS: Eleven healthy subjects and eight patients with HCM underwent velocity-encoded echo-planar magnetic resonance (MR) imaging (6-8-frame gated breath-hold movies, 3 x 3-mm resolution). A scalar strain rate (SR) parameter was compared with wall thickness and symptoms. RESULTS: The normal pattern of SR included regional uniformity, a monotonically increasing subepicardial to subendocardial gradient, and minimum transmural shear rate. In HCM, heterogeneity of SRs increased in diastole. Regional diastolic SR correlated with regional wall thickness (r = .785, P = .0001). Interobserver global SR assignment agreed in seven of eight patients. All four patients with New York Heart Association class 1 disease had a low global SR deficit score, whereas three of four patients with class 2 or 3 disease had a high SR deficit score (Spearman r = .775, P = .187). CONCLUSION: SR characterization may provide an objective measure of disease course in HCM.

Adolescent↗
PubMed1994

A clinical rule to predict preserved left ventricular ejection fraction in patients after myocardial infarction.

OBJECTIVE: To derive and validate a clinical prediction rule that identifies patients after myocardial infarction who have preserved left ventricular systolic function. DESIGN: Retrospective analysis of a prospective cohort study, with a derivation set to generate a clinical prediction rule and a validation set to test the prediction rule. SETTING: Urban tertiary care hospital. PATIENTS: 314 consecutive patients admitted with myocardial infarction who had one or more of the following tests to determine left ventricular ejection fraction: transthoracic echocardiography, contrast left ventriculography, or radionuclide ventriculography. MEASUREMENTS: Left ventricular ejection fractions were determined by transthoracic echocardiography, contrast left ventriculography, and gated blood pool scan. RESULTS: Multivariate analysis of patients in the derivation set yielded the following rule: The left ventricular ejection fraction is predicted to be 40% or more in patients who have 1) an interpretable electrocardiogram, 2) no previous Q-wave myocardial infarction, 3) no history of congestive heart failure, and 4) an index myocardial infarction that is not a Q-wave anterior infarction. In the derivation and the validation sets, the positive predictive value of the prediction rule was more than 0.98. CONCLUSIONS: A simple clinical prediction rule using easily obtained historical and electrocardiographic data reliably identifies a substantial percentage of patients after myocardial infarction (40% in our hospital) who are likely to have preserved left ventricular systolic function. If validated in other patient populations, application of this prediction rule in clinical practice could result in a substantial decrease in the cost of treating uncomplicated myocardial infarction.

Aged↗