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Abstract

Introduction: Although a reduction in heart rate with beta blockers is considered a primary goal of the medical management of acute aortic dissection as well as reduced blood pressure, little evidence exists regarding the need for a reduction in postoperative heart rate after repair of type A acute aortic dissection. Hypothesis: We hypothesize that a lower heart rate improves the long-term outcome after surgical repair of type A acute aortic dissection. Methods: We retrospectively reviewed patients who underwent surgical repair of a type A acute aortic dissection between 1990 and 2011. Based on the average heart rate on postoperative days 1, 3, 5, and 7, 435 patients were divided into four groups, A: <70 bpm (n=19), B: 70-79 bpm (n=88), C: 80-89 bpm (n=162), and D: >90 bpm (n=166) to evaluate the impact of heart rate on ten year mortality and incidence of aortic events. Results: The median age was 65 (range 55-72) years, M:F ratio was 51:49, and initiation of beta blockers within seven days was 44%. During a median follow-up of 50.3 months, cumulative survival rate from the admission in all groups was 96.6% within 1 month, 92.9% within 1 year, 81.4% within 5 years, 54.3% within 10 years, respectively. Cumulative aortic event free rate in all groups was 98.3% within 1 month, 95.6% within 1 year, 91.1% within 5 years, 79% within 10 years, respectively. The probability of survival among the groups using Kaplan-Meier estimates revealed that there was no significant difference (A vs B, P=.815, A vs C, P=.335, A vs D, P=.416) using the log-rank test. The probability of aortic events free was also not significantly different (A vs B, P=.269, A vs C, P=.352, A vs D, P=.261). Cox proportional regression analysis showed that important predictors of mortality were age, continuous renal replacement therapy, perioperative stroke, aortic valve replacement, hospital aortic rupture. Neither stratified heart rate nor beta blocker use was significant. Conclusions: Postoperative average heart rate was not associated with increased ten year mortality or incidence of aortic events. Medical therapy to reduce the heart rate after surgery for patients with type A acute aortic dissection may not be clinically significant.