The effect of pretreatment with renin-angiotensin-aldosterone system blockers on cardioversion success and acute recurrence of atrial fibrillation

Predictors of the need for pacemaker implantation after the Cox maze IV procedure for atrial fibrillation

PURPOSE

The Cox maze IV (CMIV) procedure is being used increasingly frequently for surgical ablation of atrial fibrillation (AF). This study aimed to identify the risk factors of the need for postoperative pacemaker implantation (PMI) after CMIV.

METHODS

Preoperative, intraoperative, and postoperative data were retrospectively collected from 67 consecutive patients who underwent CMIV at our institution; 7 (10.4%) required PMI (as a treatment of brady AF or sick sinus syndrome).

RESULTS

Patients who needed PMI tended to have lower preoperative heart rates than those who did not on a 12-lead electrocardiogram (ECG; 68.7 ± 11.6 vs. 79.1 ± 18.5 bpm, p = 0.07) and a 24-h ECG (94,772 ± 9800 vs. 109,854 ± 19,078 beats/day, p = 0.03). A multivariate analysis identified a low amplitude of the fibrillatory wave on preoperative ECG as a risk factor of PMI necessity after CMIV [odds ratio = 14.7; 95% confidence interval (CI) 1.9-324.7; p = 0.007] and internal use of angiotensin-converting enzyme inhibitors or angiotensin receptor blockers (ACEIs/ARBs) as a negative risk factor (odds ratio = 0.16; 95% CI 0.02-0.99; p = 0.049).

CONCLUSIONS

A low amplitude of the fibrillatory wave was identified as a risk factor of PMI necessity, whereas the internal use of ACEIs/ARBs diminished the need for PMI. These factors should be considered before CMIV is performed.

Use of statins and recurrence of atrial fibrillation after catheter ablation or electrical cardioversion

Statins have important pleiotropic effects and have been shown to reduce vascular inflammation. Some evidence suggests that statins may have a role in the primary prevention of atrial fibrillation (AF), whereas little is know on the role of statins in patients with existing AF. We performed a meta-analysis of the literature to assess the effect of statins on the recurrence of AF after electrical cardioversion or ablation. MEDLINE and EMBASE databases were searched up to January 2010. Relative risks (RR) and 95% confidence intervals (CIs) were then calculated and pooled using a random-effects model. Statistical heterogeneity was evaluated through the use of I2 statistics. Sixteen studies were included in our systematic review. Statins did not reduce the risk of AF recurrence after ablation (four studies including 750 patients; RR, 1.04; 95% CI, 0.85–1.28, p=0.71; I2 = 34%). Conversely, the use of statins was associated with a significantly reduced risk of AF recurrence after electrical cardioversion (12 studies including 1790 patients; RR, 0.78; 95% CI, 0.67–0.90, p=0.0003; I2 = 34%). This reduction was not statistically significant when the analysis was restricted to randomised controlled trials (RCTs) only (five studies, 458 patients, RR, 0.76; 95% CI, 0.48–1.20). In conclusion, statins may lower the risk of AF recurrence after electrical cardioversion, but not ablation. However, this finding should be considered with caution, and larger RCTs are warranted to confirm our preliminary results.

Association between the use of renin-angiotensin system blockers and development of in-hospital atrial fibrillation in patients with ST-segment elevation myocardial infarction

BACKGROUND AND AIM

Atrial fibrillation (AF) is the most common supraventricular arrhythmia following ST-segment elevation myocardial infarction (STEMI). We evaluated the association between use of previous angiotensin converting enzyme inhibitors and/or angiotensin receptor blockers (renin-angiotensin system [RAS] blockers) and started RAS blockers after MI and development of AF in patients presenting with acute STEMI.

MATERIALS AND METHODS

This retrospective study enrolled 1000 patients with acute STEMI who were admitted to the coronary care unit. Patients were divided into groups according to the use of RAS blockers before MI and development of AF rates was compared. Predictors of AF were determined by multiple logistic regression analysis.

RESULTS

Of the 1000 patients presenting with STEMI, 247 received and 753 did not receive RAS blockers. The incidence of AF was 7.9%. The incidence of AF in patients receiving RAS blockers and did not receiving RAS blockers before MI were similar (5.7% vs. 8.6% respectively, P=0.13). On the other hand, AF rate was lower in patients in whom RAS blockers were administered during MI as compared to those in whom these agents were not administered (7.2% vs. 28.6%, P<0.001). Multiple regression analysis results showed that administration of RAS blockers or statins during hospitalization and left atrial diameter were associated with development of AF in patients with acute STEMI.

CONCLUSIONS

Previous therapy with RAS blockers does not reduce the incidence of AF in STEMI. Administration of RAS blockers at the hospital may decrease the AF rate in STEMI.

Predictors of incident atrial fibrillation and influence of medications: a retrospective case-control study

BACKGROUND

Atrial fibrillation (AF) is a common condition, associated with raised mortality and risk of major morbidity, and is predicted to increase due to an aging population.

AIM

To update earlier research of AF predictors using UK data.

DESIGN AND SETTING

Case-control analysis of adults aged 18 years and older with a diagnosis of AF in practices registered with the General Practice Research Database (GPRD) in the UK.

METHOD

Using the GPRD, a case.control analysis was performed using logistic regression to compare 55,412 incident AF cases to 216,400 controls, for medical history and prior use of drugs. The association between time since start of diagnosis or drug use and AF risk was summarised using Spline regression.

RESULTS

The following were confirmed as risk factors for AF: heart failure (risk ratio [RR] 2.91 [95% CI = 2.59 to 3.27]); ischaemic heart disease (IHD) (RR 2.00 [95% CI = 1.78 to 2.24]); hypertension (RR 2.60 [95% CI = 2.32 to 2.92]); hyperthyroidism (RR 1.56 [95% CI = 1.39 to 1.75]); being a heavy drinker (RR 1.43 [95% CI = 1.27 to 1.60]); cerebrovascular accident (RR 1.48 [95% CI = 1.32 to 1.66]); and obesity (body mass index ≥30 kg/m(2) RR 1.29 [95% CI = 1.15 to 1.45]). Current use of oral glucocorticoids (RR 1.62 [95% CI = 1.44 to 1.82]) and of beta-2 agonists (RR 1.30 [95% CI = 1.16 to 1.46]) were identified as significant risk factors, and statins (RR 0.82 [95% CI = 0.73 to 0.92]) as a significant protective factor. No effect was found for current use of bisphosphonates (RR 0.95 [95% CI = 0.85 to 1.07]), renin.angiotensin.aldosterone system (RAAS) agents (RR 1.04 [95% CI = 0.93 to 1.17]), or xanthine derivatives (RR 1.09 [95% CI = 0.97 to 1.22]). Spline regression analysis found the effect of heart failure, IHD, use of oral glucocorticoids, and use of statins on the likelihood of developing AF was sustained over a number of years.

CONCLUSION

These findings update the risk factors that are associated with AF, and confirm the protective properties of statins and the risks of beta-2 agonists in developing AF, but not the supposed protective qualities of glucocorticoids and RAAS agents.