Background: Large datasets of outcomes in cardiac rehabilitation (CR) are not often analysed using a combination of primary presentations and comorbidities, which has left important issues as yet unresolved. This study investigates the influence of history of infarction, measured pre-program resting blood pressure, and comorbidities including diagnosed hypertension, hypercholesterolemia, diabetes and obesity on CR outcomes in patients without a history of myocardial infarction (MI).

Methods: Retrospective exercise-based outpatient CR data were reviewed within the study (n = 4,202), collected between January 2000 and December 2011, consisting of observations made during pre- and post-program patient assessment processes. Resting heart rate (HR) and systolic (SBP) and diastolic (DBP) blood pressure observations in those without a history of MI (n = 1,703) were corrected for gender, assessed pre-program resting blood pressure, and comorbidities including diagnosed hypertension, hypercholesterolemia, diabetes and obesity (assessed BMI > 30).

Results: Gender differentials were observed in post-program outcomes. Additionally, assessed pre-program hypotensives (SBP < 100 mmHg) showed blood pressure increases while hypertensives (SBP > 130 mmHg) showed decreases post-program. These blood pressure outcomes were also influenced by the number of comorbidities, which further clarified post-program results and revealed potentially important trends.

Conclusion: Despite the limitations of administrative datasets, this study has demonstrated significant value in analysing such outpatient CR program data. The corrections applied in this retrospective review demonstrate the importance of considering gender, primary presentations and comorbidities when interpreting outcomes, as well as implying the need for a consideration of these factors in exercise prescription, towards pathology-specific CR and improving outcomes. More research is warranted.