Increased Incidence of A-Dissections in Weather Conditions with Rising Temperature

Objectives: Acute type A-dissection (AD) is a well-known life-threatening condition with 80% mortality within the first 24 hours if not diagnosed promptly, requiring emergency operation, which can reduce it to 20% (thirty-day mortality). In our department, 50–70 patients undergo emergency surgery for AD per year and we hypothesized if there is a correlation between this disease and weather changes. Therefore, the aim of the present study was to analyze the incidence of AD with regard to changing weather conditions.

Methods: Between January 1, 2006, and December 31, 2016, a total of 536 patients suffered an AD and were referred to our tertiary center for emergency surgery. Preoperative, intraoperative, postoperative and follow-up information were collected. Our national meteorological department provided the local data of average temperature, humidity and air pressure for every single day of these eleven years.

Results: Mean age was 63.5 ± 13years, 69% were male patients and 68.5% had documented hypertension. Supracoronary replacement was performed in 86.2%, hemiarch in 41%, total arch in 11.2%, Bentall in 25.7% of the patients. Thirty day mortality was 17.9%. Median follow up was 26 (1–133) months and was completed in 480 (90%) with 70.5 ± 2.8% survival at 3 years. The incidence of all 536 A-dissections were then analyzed in correlation with the obtained daily weather data including temperature, humidity and air pressure (constant, rising, lowering compared with the day before and after) within the entire cohort and in patients with or without hypertension separately. The results show that patients with hypertension had a 28% increased incidence for the occurrence of an AD when a temperature increase was present (0.1–9.6°C, OR: 1.28, 95% CI (1–03–1.6), p = 0.027), which was particularly evident in March, October and December (p = 0.03 with hypertension, p = 0.01 without hypertension). To the contrary, humidity and air pressure did not show any significant correlation to the occurrence of AD.

Conclusion: This study is the first one to describe a significantly increased incidence of AD in hypertensive patients in weather conditions with increasing temperature in certain months of the year. With these results, we aim to make primary centers more aware of this life-threatening disease to prevent delayed and false diagnosis in the presence of increasing temperatures and certain months of the year and allow rapid referral for emergency surgery.