Abstract

Background: Spontaneous Coronary Artery Dissection (SCAD) patients represent a rare subgroup presenting with acute coronary syndrome (ACS) who are often younger with fewer comorbidities than the average patient with coronary artery disease (CAD). It is also a condition that disproportionately affects women who appear to be more physically fit than average, although this has never been investigated.
Objectives: The purpose of this study was to determine the functional capacity of SCAD patients as compared to the average patient referred for an exercise treadmill test (ETT) in order to better inform the development of cardiovascular rehabilitation programs and exercise recommendations for these patients.
Methods: In this retrospective, case-control study, 39 women with angiographically confirmed SCAD who had undergone pre-cardiac rehabilitation ETT were identified from the Massachusetts General Hospital registry. Cases were matched by age and gender in a 1:2 fashion to controls that had undergone ETT at our institution between 2005 and 2013. ETT results were compared between the cases and controls.
Results: Women with SCAD had a significantly longer exercise duration (9.4 ± 2.0 vs. 8.0 ± 2.6 minutes, p=0.001) and a better functional capacity (11.0 ± 2.2 vs. 9.5 ± 2.7 METs, p<0.001) as compared to age and sex matched controls. SCAD cases also had a higher Duke Treadmill Score (8.8 ± 3.2 vs. 6.4 ± 3.8 METs, p<0.001) as compared to controls.
Conclusions: Women presenting with SCAD as the cause of ACS have a significantly greater functional capacity as compared to the average patient referred for an ETT. Therefore, they may require modification of the routine cardiac rehabilitation program designed for the average patient with CAD to achieve maximum benefit. The development of a safe, appropriately challenging, and highly personalized exercise rehabilitation prescription is necessary for these patients to return to their baseline activity and quality of life.

Keywords: Spontaneous coronary artery dissection; Acute coronary syndrome; Exercise stress test; Cardiac rehabilitation