Key result
Candesartan reduced the fibrillatory rate in persistent AF (399 to 388 fpm, P=0.04), but this was restricted to patients with high baseline rates and did not improve cardioversion outcome.
Why the study?
Does candesartan reduce atrial fibrillatory rate and improve cardioversion outcomes in patients with persistent atrial fibrillation?
RCT (n=124)
placebo-controlled
randomized
Does candesartan reduce atrial fibrillatory rate and improve cardioversion outcomes in patients with persistent atrial fibrillation?
Candesartan modestly reduces atrial fibrillatory rate in persistent AF patients with high baseline rates, but this does not translate to improved cardioversion success or reduced AF recurrence.
Does not improve cardioversion outcomes in persistent AF; challenges adjunctive ARB use and leaves open rate-specific mechanisms.
INTRODUCTION: Angiotensin-receptor blockers may exert favourable anti-arrhythmic effects in atrial fibrillation (AF), but their mechanisms are not fully understood. In this study, we tested the hypotheses that (i) candesartan reduces atrial fibrillatory rate and (ii) fibrillatory rate and its response to candesartan are related with the outcome of cardioversion. For this purpose, a post hoc subanalysis of the randomized, placebo-controlled CAPRAF (Candesartan in the Prevention of Relapsing Atrial Fibrillation) trial was performed. METHODS AND RESULTS: Patients with AF undergoing electrical cardioversion were randomized to receive candesartan 8 mg once daily (n = 58) or matching placebo (n = 66) and no additional class I or III anti-arrhythmic drugs. Fibrillatory rate was determined from ECG lead V1 at baseline and at the day of cardioversion using spatiotemporal QRST cancellation and time-frequency analysis. The median time on treatment was 29 days. Candesartan reduced fibrillatory rate [399 +/- 48 vs. 388 +/- 49 fibrillations/min (fpm), P = 0.04], but not placebo (402 +/- 58 vs. 402 +/- 61 fpm, P = 0.986). Candesartan effects were only observed if the baseline fibrillatory rate was high [>420 fpm: 445 +/- 21 vs. 415 +/- 49 fpm, P = 0.006 vs. intermediate (360-420 fpm): 397 +/- 19 vs. 391 +/- 37 fpm, P = 0.351 vs. low (<360 fpm): 326 +/- 26 vs. 338 +/- 29 fpm, P = 0.179]. Cardioversion success was 100% in patients with an on-treatment rate <360 fpm vs. 83% in patients with higher rates (P = 0.02). Risk for AF recurrence was similar in patients with low (64%), intermediate (75%), or high on-treatment rates (63%, P = 0.446) and was also independent of candesartan effects on the fibrillatory rate. CONCLUSION: In patients with persistent AF, candesartan decreases the fibrillatory rate, but this effect is restricted to patients with high baseline fibrillatory rates and is not associated with improved cardioversion outcome. Fibrillatory rates <360 fpm are associated with successful cardioversion, but not with AF recurrence.
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Bollmann et al. (2008) conducted an RCT in persistent atrial fibrillation (n=124). candesartan vs. placebo was evaluated on fibrillatory rate (p=0.04). Candesartan reduced the fibrillatory rate in persistent AF (399 to 388 fpm, P=0.04), but this was restricted to patients with high baseline rates and did not improve cardioversion outcome.
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