n-3 Polyunsaturated fatty acids for the prevention of postoperative atrial fibrillation: a meta-analysis of randomized controlled trials.

BACKGROUND: n-3 Polyunsaturated fatty acids (n-3 PUFAs) have been proposed as prophylactic therapy in the prevention of postoperative atrial fibrillation (POAF) in patients undergoing cardiac surgery. We conducted a meta-analysis of randomized controlled trials to better clarify this issue. METHODS: An electronic database search for randomized controlled trials on the effect of n-3 PUFAS on POAF was conducted, limited to English language publications until December 2010. For each study, data regarding the incidence of POAF were used to generate risk ratio (<1, favors n-3 PUFA; >1, favors placebo). Pooled summary effect estimate was calculated by means of a fixed or random effect according to heterogeneity. Meta-regression was used to investigate the effect of eicosapentaenoic acid (EPA)/docosahexaenoic acid (DHA) ratio and preoperative ß-blockers on the effect of n-3 PUFA on POAF. RESULTS: Three publications were included in the analysis, enrolling a total of 431 patients. Overall incidence of POAF ranged from 24 to 54%. Pooling data, n-3 PUFA did not show a significant effect on the risk of POAF [risk ratio 0.89; 95% confidence interval (CI) 0.55-1.44; P=0.63]. However, meta-regression analysis showed a trend toward a benefit from n-3 PUFA supplementation when the EPA/DHA ratio was 1:2 (Q model=7.4; p model=0.02) and when preoperative ß-blocker rate was lower (Q model=8.0; p model=0.01). CONCLUSION: In conclusion, the results of the present meta-analysis of randomized controlled trials suggest that preoperative n-3 PUFA therapy may not reduce POAF in patients undergoing cardiac surgery. However, several aspects may have influenced this negative result, which need to be investigated.

n-3 polyunsaturated fatty acids after coronary artery bypass grafting.

BACKGROUND: Despite the robust evidence of the potential benefits of n-3 polyunsaturated fatty acid (PUFA) supplementation in patients with established coronary artery disease, the impact of this therapy on patients after coronary artery bypass grafting remains completely unknown. METHODS: Among 2,100 patients undergoing isolated coronary artery bypass grafting in one tertiary care institution, 930 (44%) were put under n-3 PUFA therapy chronically at discharge. The impact of n-3 PUFAs was assessed by means of propensity-score adjusted analysis. The primary end point was all-cause mortality. Secondary end points were repeat revascularization and the composite of death, Q-wave myocardial infarction, and cerebrovascular events. RESULTS: In a crude analysis, patients discharged on n-3 PUFAs had a lower risk for late mortality (unadjusted hazard ratio [HR], 0.51; 95% confidence interval [CI], 0.36 to 0.73; p = 0.0002), which was conformed at multivariable adjusted Cox regression analysis (HR, 0.55; 95% CI, 0.26 to 0.90; p = 0.02). Adjusted risk of repeat revascularization was significantly lower in patients receiving n-3 PUFAs than in those who did not (HR, 0.52; 95% CI, 0.28 to 0.97; p = 0.04). The adjusted risk for the composite of death, Q-wave myocardial infarction, or cerebrovascular events was lower in patients who received n-3 PUFAs compared with patients who did not (HR, 0.56; 95% CI, 0.36 to 0.81; p = 0.001). Subgroup analyses showed that mortality benefit associated with n-3 PUFAs was particularly relevant in patients with poor left ventricular function (HR, 0.36; 95% CI, 0.17 to 0.76; p = 0.007), but it was only marginal in patients with good ventricular function (HR, 0.89; 95% CI, 0.65 to 1.01; p = 0.05). CONCLUSIONS: This study showed that n-3 PUFAs after coronary artery bypass grafting were associated with a lower risk for repeat revascularization and overall mortality in patients with poor ventricular function.

Dual renin-angiotensin system blockade for patients with prosthesis-patient mismatch.

BACKGROUND: Patients with prosthesis-patient mismatch (PPM) continue to show some degrees of left ventricular hypertrophy after aortic valve replacement for aortic stenosis. The renin-angiotensin system plays a major role in promoting and sustaining hypertrophy. In a controlled, randomized study, we tested the hypothesis that the combination of angiotensin-converting enzyme inhibitors (ACEi) plus angiotensin II receptor blocker (ARB) can be more effective in decreasing hypertrophy than a largely employed association such as ACEi plus ß-blockers in PPM patients. METHODS: We enrolled a total of 72 patients with aortic valve replacement and evidence of PPM (effective orifice area <0.85 cm(2)/m(2)) at postoperative echocardiography. At discharge, they were randomly assigned to ramipril plus candesartan (n = 36) or ramipril plus metoprolol (n = 36). RESULTS: At baseline, age, 24-hour blood pressure, left ventricular measurements, and transprosthetic gradients were similar between the two groups. After 12 months, the extent of 24-hour systolic and diastolic blood pressure decrease was similar between the two groups (-13.3% and 16.3% versus -12.3% and 15.8%, respectively; p = 0.7 and 0.8, respectively). Left ventricular mass index significantly decreased in both groups (ACEi plus ARB 165 ± 19 g/m(2) to 117 ± 17 g/m(2); p < 0.0001; ACEi plus ß-blockers 161 ± 15 g/m(2) to 128 ± 20 g/m(2); p < 0.0001). However, patients receiving ACEi plus ARB had a higher decrease of left ventricular mass (-46 ± 15 g/m(2) versus -35 ± 12 g/m(2); p = 0.001) and a lower rate of residual left ventricular hypertrophy (22% versus 47%; p = 0.04). CONCLUSIONS: This study shows that in patients with PPM, the association ACEi and ARB has a greater antiremodeling effect compared with ACEi and ß-blockers, and is independent of blood pressure.