Cardiac Rehabilitation and Blood Pressure E23C ardiovascular disease (CVD) remains a leading cause of morbidity and mortality in industrialized nations. 1 Prevention of recurrent CVD is linked to healthy lifestyles and risk factor mitigation. Notably, regular exercise prevents disease, but given the frequency of CVD diagnoses, exercise-based cardiac rehabilitation (CR) is essential for preventing disease recurrence. [2][3][4][5] The benefits of exercise extend to CVD risk factor management, including the control of blood pressure (BP), one of the most well-established benefits experienced by active individuals. 6 Hypertension contributes directly to many cardiac pathologies (eg, ischemic heart disease, heart failure), and hypertension is among the most modifiable CVD risk factors, whereas a 10-mm Hg drop in BP is associated with 50% lower rates in all-cause mortality. 7 Accordingly, recent Global Burden of Disease Study findings demonstrate that elevated systolic blood pressure (SBP) is among the most important contributing factors to all-cause disability. 8 Given need to improve BP management in at-risk persons, the American College of Cardiology (ACC)/American Heart Association (AHA) released revised hypertension guidelines in 2017, lowering diagnostic hypertension thresholds from 140/90 mm Hg to 130/80 mm Hg. 9 The revised guidelines reclassify the pernicious effects of hypertension by delineating pre-hypertension from stage 1 and stage 2 hypertension according to more rigorous standards, lowered in 10 mm Hg increments.Accordingly, lowering BP through comprehensive CR approaches is among the most impactful first-line treatments 10 ; however, the impact of the new BP guidelines is incomplete. Preliminary findings from a retrospective study indicated that CR reduces all-cause mortality in the approximately 6 yr of follow-up investigation, but the contribution of rehabilitative exercise to risk factor modifications, including BP, was not delineated. Successful control of SBP is nonetheless recognized as essential to long-term cardiovascular health in that CR participation is linked to declines in visit-to-visit SBP. 11 Based on this rationale, it is clear that exercise rehabilitation improves cardiovascular health, at least in part due to improvements in BP 2,10,12 ; however, several fundamental questions remain unresolved. For instance, (1) how much does rehabilitative exercise alter BP in the average CR patient? (2) Since phase II CR visits typically range between 12 and 36 visits, is there a dose response effect on BP? In addition, (3) do demographic factors (sex, race, etc), referring diagnoses, or the influence of the insurance provider alter BP? Finally, (4) it is unknown whether institution of the new ACC/AHA guidelines 12 has impacted BP in patients referred to CR. According to this rationale, we sought to answer these questions about the influence of CR on BP.
METHODS
CR REGISTRY AND PATIENT DATA COLLECTIONThese data were collected from the Montana Outcomes Project, a data registry developed and coordi...