Abstract Background Many patients receiving amiodarone therapy are male. The long-term risk for amiodarone-induced thyroid dysfunction in these patients has not been systematically and prospectively ...investigated. The purpose of this study was to determine the extent of amiodarone-induced thyroid dysfunction in a large male cohort. Methods This is a substudy of a prospective randomized controlled trial (SAFE-Trial) in which amiodarone, sotalol, and placebo for persistent atrial fibrillation were evaluated. For the purpose of this substudy, sotalol and placebo groups were combined into a control group. Serial thyroid function tests were performed over 1-4.5 years. Of the 665 patients enrolled in the SAFE-Trial, 612 patients were included in this sub-study. Results Subclinical hypothyroidism, thyroid-stimulating hormone (TSH) level 4.5-10 mU/L, was seen among 25.8% of the amiodarone-treated patients and only 6.6% of controls ( P <.0001). Overt hypothyroidism, TSH level >10 mU/L, was seen among 5.0% of the amiodarone-treated patients, and only 0.3% of controls ( P <.001). By 6 months, 93.8% of the patients who developed TSH elevations above 10 mU/L on amiodarone had been detected. There was a trend toward a greater proportion of hyperthyroidism, defined as a TSH <0.35 mU/L, in the amiodarone group compared with the control group (5.3% vs 2.4%, P = .07). Conclusions Hypothyroidism developed in 30.8% of older males treated with amiodarone and in only 6.9% of the controls. Hypothyroidism presented at an early stage of therapy. Hyperthyroidism occurred in 5.3% of amiodarone treated patients, and was a subclinical entity in all but 1 case.
The Coronary Artery Revascularization Prophylaxis (CARP) study showed no survival benefit with preoperative coronary artery revascularization before elective vascular surgery. The generalizability of ...the trial results to all patients with multivessel coronary artery disease (CAD) has been questioned. The objective of this study was to determine the impact of prophylactic coronary revascularization on long-term survival in patients with multivessel CAD. Over a 4-year period, 1,048 patients underwent coronary angiography before vascular surgery during screening into the CARP trial. The cohort was composed of registry (n = 586) and randomized (n = 462) patients, and their survival was determined at 2.5 years after vascular surgery. High-risk coronary anatomy without previous bypass surgery included 2-vessel disease (n = 204 19.5%), 3-vessel disease (n = 130 12.4%), and left main coronary artery stenosis ≥50% (n = 48 4.6%). By log-rank test, preoperative revascularization was associated with improved survival in patients with a left main coronary artery stenoses (0.84 vs 0.52, p <0.01) but not those with either 2-vessel (0.80 vs 0.79, p = 0.83) or 3-vessel (0.79 vs 0.71, p = 0.15) disease. In conclusion, unprotected left main coronary artery disease was present in 4.6% of patients who underwent coronary angiography before vascular surgery, and this was the only subset of patients showing a benefit with preoperative coronary artery revascularization.
Background Therapy for chronic atrial fibrillation (AF) focuses on rate versus rhythm control, but little is known about the effects of common therapeutic interventions on exercise tolerance in AF. ...Methods Six hundred fifty-five patients with chronic AF underwent maximal exercise testing at baseline and 8 weeks, 6 months, and 1 year after randomization to sotalol, amiodarone, or placebo therapy and attempted direct current cardioversion. Analyses of baseline determinants of exercise capacity, predictors of change in exercise capacity at 6 months and 1 year, and the short- and long-term effects of cardioversion on exercise capacity were made. Results Age, obesity, and presence of symptoms accompanying AF were inversely associated with baseline exercise capacity, but these factors accounted for only 10% of the variance in exercise capacity. Patients most likely to benefit from cardioversion were those most limited initially, younger, not obese or hypertensive, and with an uncontrolled ventricular rate at baseline. Conversion to sinus rhythm (SR) resulted in significant reductions in resting (≈25 beat/min) and peak exercise (≈40 beat/min) heart rates at 6 months and 1 year ( P < .001). Successful cardioversion improved exercise capacity by 15% at 8 weeks, and these improvements were maintained throughout the year. This improvement was observed both among those who maintained SR and those with intermittent AF. Conclusion Cardioversion resulted in a sustained improvement in exercise capacity over the course of 1 year, and this improvement was similar between those in SR and those with SR and recurrent AF. Patients most likely to improve with treatment tended to be younger and nonobese and have the greatest limitations initially.
Background Preoperative cardiac risks and clinical indications for vascular surgery are both important determinants of outcome following a vascular operation. Using the nonrandomized cohort from the ...Coronary Artery Revascularization Prophylaxis (CARP) Trial, we analyzed the predictors of outcome based on the presenting vascular problem and prevalence of comorbid conditions and cardiac risks. Methods and Results Between March 1, 1999 and February 28, 2003, 4414 patients were ineligible for randomization in the CARP Trial and their survival was retrieved through the BIRLS system (the Department of Veterans Affairs Beneficiary Identification and Records Locator Subsystem). Surgical indications were either an abdominal aortic aneurysm (N = 1598) or lower extremity ischemia for claudication (N = 1116), rest pain (N = 670), or tissue loss (N = 1030). Patients were screened for major cardiac risks that included a history of angina, congestive heart failure, myocardial infarction, ventricular arrhythmias, pathological q-waves, and diabetes. The absence of multiple cardiac risks, as the sole reason for exclusion from randomization, occurred in 2314 (52.4%) screened patients and their probability of survival at 2.5-year post-surgery was 0.88. This was better than the survival of the remaining excluded patients (N = 2100), which was 0.75 ( P < .0001) and the randomized cohort (N = 462), which was 0.80 ( P < .0001). By Cox regression analysis, urgent surgery, congestive heart failure, ventricular arrhythmias and creatinine >3.5 mg/dL were significantly associated with long-term postoperative mortality. Conclusions Patients without multiple cardiac risks or comorbid conditions have a good outcome following elective vascular surgery. Urgent surgery, creatinine >3.5 mg/dL, congestive heart failure, and ventricular arrhythmias are identifiers of a poor long-term outcome and may justify aggressive strategies for risk-stratification in the postoperative period.
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