Impact of epicardial anterior fat pad retention on postcardiothoracic surgery atrial fibrillation incidence: the AFIST-III Study.

OBJECTIVES: We conducted a randomized, blinded, controlled study evaluating the impact of anterior fat pad (AFP) maintenance on postoperative atrial fibrillation (POAF) incidence. BACKGROUND: Drugs with antiadrenergic effects reduce POAF. Because the epicardial AFP is parasympathetically innervated, its routine excision during coronary artery bypass grafting (CABG) might precipitate autonomic imbalance and induce POAF. METHODS: Patients (n = 180, mean age = 66 +/- 10 years, 80% men, 5% with previous atrial fibrillation) undergoing CABG surgery were randomized to either AFP maintenance or AFP removal. Routine prophylaxis against POAF with beta-blockers (85%) and amiodarone (28%) was allowed on the basis of caregivers' discretion. The development of POAF, total hospital costs, and heart rate variability was compared between groups. RESULTS: Anterior fat pad maintenance did not reduce POAF incidence (34.8% vs. 35.2%, p = 0.950) or total hospital costs (data as medians with 25%, 75% percentiles: 22,940 dollars [17,629 dollars, 29,274 dollars] vs. 23,866 dollars [18,602 dollars, 30,370 dollars], p = 0.647) but was associated with higher heart rate variability (SD of normal-to-normal RR intervals [SDNN]: 31.7 +/- 24.6 vs. 22.7 +/- 8.3, p = 0.05 and SD of all 5-min mean RR intervals [SDANN 5]: 17.1 +/- 11.9 vs. 10.1 +/- 5.5, p = 0.003) than AFP removal. CONCLUSIONS: Maintaining the AFP prevents attenuation of parasympathetic tone after CABG but does not reduce POAF or total hospital costs in any appreciable way.

Postpartum dissection of the left main coronary artery.

Peripartum coronary artery dissection is rare, but it is an increasingly recognized risk to women of childbearing age. Literature reviews reveal that about 80% of the population with spontaneous coronary artery dissections (SCAD) are female, and approximately 25-33% of cases occurred while the woman was pregnant or in the peripartum phase. Most cases have presented within 2 weeks of delivery. The left anterior descending is the most commonly affected vessel. The etiology is poorly understood, but many reports suggest that SCAD occurs as a result of protease release secondary to an eosinophilic vasculitis resulting in vessel lysis. Many investigators have examined the correlation between peripartum SCAD and estrogen levels; however, case studies have shown conflicting results regarding estrogen levels as the putative causative factor. Optimal treatment remains controversial. Presently, stenting appears to be best employed in the patients who have single-vessel dissection not involving the left main coronary artery (LMCA). Surgical revascularization via coronary artery bypass graft remains the optimal therapy in patients whose dissection involves the LMCA, in patients with concurrent multivessel dissection, and in patients with disease refractory to medical management. It is important to consider coronary artery dissection in the differential of any young woman who presents with signs or symptoms consistent with acute coronary syndrome, particularly if she is peripartum. Furthermore, once suspected, it is imperative that a definitive diagnostic study, that is, coronary angiography, be completed prior to the initiation of treatment whenever possible.

Effect of aprotinin on the frequency of postoperative atrial fibrillation or flutter.

PURPOSE: The relationship between adding aprotinin to standard care and the frequency of postoperative atrial fibrillation or flutter (POAF) in patients undergoing cardiothoracic surgery (CTS) with cardiopulmonary bypass (CPB) was studied. METHODS: This was a retrospective cohort evaluation. All patients at a hospital who underwent CTS with CPB between October 1999 and October 2003 and who received aprotinin during surgery were included in the treatment group. Control patients were those who did not receive aprotinin; they were matched with treatment group patients for age, valvular surgery, history of atrial fibrillation or flutter, renal dysfunction, peripheral artery disease, smoking, angina, diabetes mellitus, congestive heart failure, previous CTS, sex, beta-blocker intolerance, and use of preoperative digoxin. The primary endpoint was POAF; secondary endpoints were perioperative transfusion use, length of stay (LOS), stroke, myocardial infarction, renal failure, graft occlusion, and death. RESULTS: A total of 438 patients (219 per group) were evaluated. The patients' mean age was 68 years, 67% were men, and 74% had had valvular surgery. Patients who received aprotinin (mean +/- S.D. dose, 2.75 million +/- 1.24 million kallikrein-inhibiting units) did not have a significantly lower frequency of POAF than control patients (28% versus 27%, respectively [p = 0.92]), nor was there a significant difference in secondary endpoints. CONCLUSION: Aprotinin therapy was not associated with a significant reduction in POAF in patients undergoing CTS with CPB. Perioperative transfusion use, LOS, stroke, myocardial infarction, renal failure, graft occlusion, and mortality also did not differ significantly between aprotinin and control groups.

An evaluation of postoperative P-wave variables after cardiothoracic surgery.

Postoperative atrial fibrillation is common after cardiac surgery. Prediction of which patients will develop postoperative atrial fibrillation would be clinically useful. Increased P-wave duration, suggesting atrial conduction delay and measured from preoperative electrocardiograms, predicts postoperative atrial fibrillation. However, postoperative P-wave duration has not been evaluated after cardiac surgery. In this study, we evaluated postoperative P-wave variables (maximum P-wave duration and P-wave dispersion) over 5 days in cardiac surgery patients receiving amiodarone, pacing or no atrial fibrillation prophylaxis. P-wave variables gradually shortened as time passed from surgery. Amiodarone did not shorten P-wave measurements throughout therapy, while pacing shortened P-waves in the immediate postoperative period; however, shortening was not sustained. P-waves did not differ between those who did and did not develop atrial fibrillation with amiodarone or pacing. Our findings suggest that atrial conduction delay resulting from cardiothoracic surgery tends to resolve over time and may not play a critical role in the etiology of postoperative atrial fibrillation.