Non-atherosclerotic acute cardiac syndromes: spontaneous coronary artery dissection and Takotsubo syndrome. Comparison of long-term clinical outcomes

Background Spontaneous coronary artery dissection (SCAD) and Takotsubo syndrome (TTS) constitute two common causes of nonatherosclerotic acute cardiac syndrome particularly frequent in women. Currently, there is no information comparing long-term clinical outcomes in unselected patients with these conditions.Methods We compared the baseline characteristics, in-hospital outcomes, and the 12-month and long-term clinical outcomes of two large prospective registries on SCAD and TTS.Results A total of 289 SCAD and 150 TTS patients were included; 89% were women. TTS patients were older with a higher prevalence of cardiovascular risk factors. Precipitating triggers were more frequent in TTS patients, while emotional triggers and depressive disorders were more common in the SCAD group. Left ventricular ejection fraction was lower in TTS patients, but SCAD patients showed higher cardiac biomarkers. In-hospital events (43.3% vs. 5.2%, P<0.01) occurred more frequently in TTS patients. TTS patients also presented more frequent major adverse events at 12-month (14.7% vs. 7.1%, HR 5.3, 95% CI: 2.4-11.7, P<0.01) and long-term (median 36 vs. 31 months, P=0.41) follow-up (25.8% vs. 9.6%, HR 4.5, 95% CI: 2.5-8.2, P<0.01). Atrial fibrillation was also more frequent in TTS patients. Moreover, TTS patients presented a higher 12-month and long-term mortality (5.6% vs. 0.7%, P=0.01; and 12.6% vs. 0.7%, P<0.01) mainly driven by noncardiovascular deaths.Conclusion Compared to SCAD, TTS patients are older and present more cardiovascular risk factors but less frequent depressive disorder or emotional triggers. TTS patients have a worse in-hospital, mid-term, and long-term prognosis with higher noncardiac mortality than SCAD patients.