Author + information
- Jacqueline Saw, MD∗ (, )
- Karin Humphries, DSc and
- G.B. John Mancini, MD
- ↵∗Division of Cardiology, Vancouver General Hospital, 2775 Laurel Street, 9th floor, Vancouver, British Columbia V5Z 1M9, Canada
We thank Dr. Krittanawong and colleagues for their insightful comments on the potential synergistic effects of beta-blockers and cardiac rehabilitation (CR). Although the benefits of beta-blockers and CR were well established for patients who had atherosclerotic myocardial infarction, the value of both therapies after myocardial infarction caused by spontaneous coronary artery dissection (SCAD) was only recently explored. For patients with SCAD, our study showed the benefit of beta-blockers, which were associated with a substantial reduction of recurrent SCAD events (1). Limited studies had explored the safety and efficacy of CR post-SCAD (2–4).
Retrospective series of patients with SCAD who underwent standard CR programs suggested improvements in emotional and physical wellbeing (3,4). At our institution, a centralized and concentrated SCAD patient cohort enabled us to establish a dedicated SCAD-CR program, which was tailored to the unique exercise and psychosocial demands of survivors of SCAD (2). Our modified exercise therapy consisted of aerobic activities with initial low-level targets for heart rate and blood pressure (titrated to perceived exertion of moderate to somewhat difficult) and light resistance training with 2- to 12-lb weight repetitions. Mindful living sessions and psychosocial support and counseling with SCAD peers, case managers, a social worker, and a psychiatrist were available. We reported our SCAD-CR program to be safe and beneficial in the first prospective cohort of 70 patients, with improvements in exercise capacity and psychosocial measures and reduction in chest pain post-SCAD. Furthermore, the long-term cardiovascular event rate was lower compared with patients who did not participate in SCAD-CR (4.3% vs. 26.2%; p < 0.001). Interestingly, ∼85% of our SCAD-CR patients were taking a beta-blocker, which may have played a role in the reduction of cardiovascular events. In addition, we routinely advise patients with SCAD to avoid intense isometric activities (avoiding weights >30 lbs) and competitive sports and to minimize emotional stress. We presume that the mechanisms of long-term benefits were additive from beta-blocker use, exercise rehabilitation, and avoidance of triggers.
Although the current available supportive data are limited, we agree with Dr. Krittanawong and colleagues that beta-blockers and CR should be routinely administered and recommended, respectively, after a SCAD event. Even though a SCAD-specific CR program is unavailable outside Vancouver, we believe that standard CR programs are still beneficial to patients with SCAD, with recommended modifications to exercise training and psychosocial support as outlined in our protocol.
Please note: Dr. Saw has received unrestricted research grant support from the Canadian Institutes of Health Research, Heart & Stroke Foundation of Canada, University of British Columbia Division of Cardiology, AstraZeneca, Abbott Vascular, St. Jude Medical, Boston Scientific, and Servier; has received speaker honoraria from AstraZeneca, St. Jude Medical, Boston Scientific, and Sunovion; has received consultancy and advisory board honoraria from AstraZeneca, St. Jude Medical, and Abbott Vascular; and has received proctorship honoraria from St. Jude Medical and Boston Scientific. All other authors have reported that they have no relationships relevant to the contents of this paper to disclose.
- 2018 American College of Cardiology Foundation