Prophylactic oral amiodarone compared with placebo for prevention of atrial fibrillation after coronary artery bypass surgery.

BACKGROUND: Postoperative atrial fibrillation occurs in 20% to 40% of patients undergoing coronary artery bypass grafting (CABG) and contributes to delayed recovery, increased length of stay, and increased hospital cost. Measures at preventing postoperative atrial fibrillation have had mixed results. We report a double-blind trial comparing oral amiodarone with placebo for the prevention of atrial fibrillation after CABG. METHODS AND RESULTS: All patients undergoing CABG were considered eligible. Exclusion criteria included bradycardia (<50 beats/min), prior Atrial fibrillation, concurrent therapy with antiarrhythmic drugs, or concomitant valve surgery. Patients were given 2 g of amiodarone (73 patients) or placebo (70 patients) in divided doses 1 to 4 days before surgery and 400 mg daily for 7 days postoperatively. Atrial fibrillation occurred in 24.7% (18 of 43) of patients receiving amiodarone and 32. 8% (23 of 70) of patients receiving placebo (P =.30). Heart rate at onset of atrial fibrillation was 133.4 +/- 26.6 beats/min for amiodarone compared with 152.9 +/- 31.6 beats/min for placebo (P =. 04). Duration of atrial fibrillation was 10.2 +/- 8.1 hours for amiodarone compared with 16.2 +/- 27.5 hours for placebo (P =.67). Patients receiving both beta-blockade and amiodarone had a 16.7% incidence of atrial fibrillation compared with 31.9% in the remaining patients (P =.10). Atrial fibrillation was associated with an increased cost of $7011 compared with those who remained in sinus rhythm ($23,869 +/- $20,894 vs $16,857 +/- $5401 in sinus rhythm). Hospital cost of those taking amiodarone was $18,895 +/- $13,267 compared with $18,839 +/- $11,537.18 for placebo (P =.42). CONCLUSION: Postoperative CABG atrial fibrillation is associated with prolonged hospital stay and increased cost. Prophylactic oral amiodarone did not statistically alter the incidence or duration of atrial fibrillation after CABG, although favorable trends were noted. Hospital cost was not affected by therapy with amiodarone.

Coronary artery bypass and valve replacement in octogenarians.

A total of 325 patients, aged 80 to 92 (mean 82), underwent cardiac operations with cardiopulmonary bypass over a 4-year period (1991-1995). Hypothermia (22 degrees C) and hyperkalemic cardioplegia were used in each. Coronary bypass procedures only (Group I) were performed in 255 patients with 22 early deaths (8.6%), and the average number of grafts was 3.7 per patient. Single or double valve replacement, with coronary bypass (Group II) was performed in 46 patients, with six early deaths (13%). Single or double valve replacement, without coronary bypass (Group III) was performed in 24 patients, with two early deaths (8.3%). Total hospital mortality was 30 deaths in 325 patients (9.2%). Fifty-six procedures (22%) from Group I and four (9%) from Group II were performed as emergencies, and all operations in Group III were elective. Seventy-two patients (27%) from Group I, 18 patients (39%) from Group II, and nine patients (37%) from Group III had major complications including renal failure, cerebrovascular accident, myocardial infarction, postoperative hemorrhage, sepsis, and ventilatory dependency. Mean hospital stay was 10.5 days for Group I, 13.3 days for Group II, and 15.2 days for Group III, with an overall mean of 13 days (range, 6-52) days. Higher mortality was related to a cardiac index <1.8, cardiogenic shock, emergency operation, creatinine >2.0, and morbid obesity. Mean left ventricular ejection fractions were 0.51 for Group I, 0.45 for Group II, and 0.49 for Group III. Preoperative risk factors associated with a higher mortality included hypertension, smoking, diabetes, and pulmonary hypertension. Two hundred seventy-two of the 299 operative survivors were followed for a mean of 18 (range, 3-52) months. The actuarial survival of octogenarians is 92 per cent, 80 per cent, and 65 per cent at 1, 3, and 5 years, respectively, and of the patients surviving operation it was 85 per cent, 70 per cent, and 55 per cent at 1, 3, and 5 years, respectively. At postoperative follow up, 80 per cent of the survivors reported an active functional status, and there was a low incidence of cardiac-related deaths.

Radiographic detection of strut separations in Björk-Shiley convexo-concave mitral valves.

BACKGROUND: The outlet struts of Björk-Shiley convexo-concave heart valves can occasionally fracture. By December 31, 1994, 564 complete strut fractures had been reported to the manufacturer, approximately two thirds of which were fatal. There are no reliable diagnostic methods to detect valves that may be at risk for strut fracture. The outlet strut has two legs, and one leg often appears to break before the other, potentially permitting detection of the single-leg separation while the valve is still functionally intact. METHODS: We used high-resolution cineradiography and defined valve profiles to evaluate 315 patients selected on the basis of their having mitral convexo-concave valves with an estimated fracture rate of 0.46 percent or higher per year. Two examinations were scheduled six months apart, with early reimaging performed when initial ratings were indeterminate. RESULTS: Three patients had unsatisfactory studies, the most recent examinations in 277 patients were rated as apparently normal, 23 had findings considered minimally suspicious, and 1 had findings termed suspicious. The number of false negative results in this study group is unknown. Eleven cineradiograms were rated as showing probable or definite single-leg separations. All five "definite" ratings and five of the six "probable" ratings were confirmed by removal of the valves. One valve with a "probable" rating was intact. Two complete outlet-strut fractures occurred three and seven months after apparently normal radiographic examinations. Unsuspected new positive findings were not found at six months among 288 patients who completed the examination cycle. CONCLUSIONS: Cineradiographic imaging can detect some single-leg separations in mitral convexo-concave valves and may help the estimated 41,000 patients with these valves worldwide and their physicians decide about elective valve removal.

Characteristics of cerebrovascular accidents after coronary artery bypass grafting.

The records of all patients who had a cerebrovascular accident (CVA) following coronary artery bypass surgery were reviewed to determine the incidence, etiology, and outcome following such an event. Between January 1, 1987, and December 31, 1990, 3,428 patients underwent bypass grafting and 46 had a CVA, documented by head computed tomography (CT) after neurologic findings were appreciated, for an incidence of 1.3 per cent. In 16 patients, a neurologic deficit was documented less than 12 hours after surgery and was presumed to have been an intraoperative event. The remaining 30 patients became symptomatic between postoperative days 2 and 7. Twenty-five patients (54%) exhibited neurologic and CT findings suggestive of an embolic event, while the remaining 21 patients appeared to have sustained an infarct as a result of cerebral hypoperfusion. Nine patients with CVA had a carotid bruit documented in the preoperative period, and seven of these suffered their ischemic event in the ipsilateral distribution. Five patients had a documented CVA previously, and four were shown to have extended areas of previous infarction. The mortality following CVA was 35 per cent. Of the survivors, 70 per cent had some improvement in symptoms at the time of discharge; 60 per cent of survivors were discharged to their homes and the remainder to extended care facilities. Although CVA following coronary bypass grafting is an uncommon event, some patients at increased risk may benefit from more aggressive preoperative noninvasive evaluation and intraoperative monitoring. A better understanding of the etiology of postoperative stroke may help to prevent its high morbidity and mortality, which has been demonstrated.

Emergency thoracotomy: a four-year review.

The case records of 200 patients who had emergency thoracotomy for penetrating trauma were reviewed. The mortality was 47% (93/200) for the entire series, 27% (21/79) for stab wounds and 60% (72/121) for gunshot wounds. Of 55 patients who underwent thoracotomy in the emergency department, 8 (15%) survived. Twelve patients "dead" at the scene could not be resuscitated. Nineteen patients sustained cardiac arrest in the ambulance, 3 (16%) of whom survived. Of 19 who had cardiac arrest in the emergency department, 5 (26%) survived. Of 38 patients who had cardiac arrest in the ambulance or emergency department, 14 with stab wounds had a 43% survival and 24 with gunshot wounds had a survival of only 8%. Patients who underwent thoracotomy in the operating room (OR) had a higher survival, 68% (99/145). For those with thoracic, extremity, or neck injuries, survival was 81% (93/115). For those who had an OR thoracotomy for aortic cross-clamping because of abdominal injuries, survival was only 17% (5/30). Early thoracotomy has a place in the management of patients who have cardiac arrest in the ambulance or emergency department because of penetrating chest, neck, or extremity injuries, especially if caused by stab wounds. Cross-clamping of the thoracic aorta for massive abdominal bleeding should be applied selectively.

An investigation of the Mini-Mult validity scales.

Examined the ability of the Mini-Mult validity scales to detect invalid MMPI profiles. When 34 invalid MMPI profiles were rescored with the Mini-Mult only 17 of the 34 profiles invalidated by the full MMPI were detected with the Mini-Mult. This included 14 of 27 profiles invalidated by an elevated F scale; 2 of 4 profiles invalidated by an elevated L scale and 1 of 3 profiles invalidated by an elevated K scale. Only 14 of 27 profiles invalidated by an F-K ratio of K11 were detected. When new conversion values for the Mini-Mult were utilized, the detection rate improved considerably for the F scale and the F-K ratio.