Organizational and patient-level predictors for reaching key risk factor targets in cardiac rehabilitation after myocardial infarction – the perfect-CR study
Authors: Ogmundsdottir Michelsen H , Henriksson P , Wallert J , Back M , Sjolin I , Schlyter M , Hagstrom E , Kiessling A , Held C , Hag E , Nilsson L , Schiopu A , Zaman M J , Leosdottir M 
Published: October 2021

Abstract

Background
The benefits of specific cardiac rehabilitation (CR) programme components on patient outcomes after myocardial infarction (MI) remain unclear, as does their relative predictive strength compared to patient-level predictors.

Purpose
To identify CR organizational and patient-level predictors for reaching risk factor targets at one-year post-MI.

Methods
This was an observational survey- and registry-based study. Data on CR organization at all 78 CR centres in Sweden was collected in 2016 and merged with individual patient data from nationwide registries (n=7549, median age 64 years, 24% females). Cross-validation resampled orthogonal partial least squares discriminant analysis identified predictors for reaching treatment targets for low-density lipoprotein-cholesterol (LDL-C&lt;1.8 mmol/L), blood pressure (BP&lt;140/90 mmHg) and smoking abstinence (yes/no). Predictors with Variables of Importance for the Projection (VIP) value &gt;0.8 and 95% confidence intervals (CI) excluding zero, were considered meaningful.

Results
Of the 71 analysed organizational variables, 36 were identified as meaningful predictors for reaching LDL-C and 35 for BP targets (Figure 1). The strongest predictors (VIP [95% CI]) for LDL-C and BP were: offering psychosocial management at initial CR assessment 2.09 [1.70–2.49]; 2.34 [1.90–2.78], having a CR team psychologist 1.59 [1.28–1.91]; 2.00 [1.46–2.55], having extended CR centre opening hours 2.17 [1.95–2.40]; 1.51 [1.03–2.00], staff reporting satisfaction with CR centre facilities 1.55 [1.07–2.04]; 1.96 [1.64–2.28], having a medical director 1.71 [1.45–1.97]; 1.47 [1.07–1.87], nurses using protocols for antihypertensive and/or lipid lowering medication adjustment 1.58 [1.35–1.81]; 1.56 [1.03–2.08], having operational team meetings 1.36 [1.08–1.64]; 1.34 [0.99–1.70], and using audit data for quality improvement 1.00 [0.79–1.20]; 1.27 [0.99–1.56]. Offering pre-exercise-based CR (exCR) assessment and different modes of exCR were predictors for reaching both targets. The strongest patient-level predictor of reaching LDL-C target was low baseline LDL-C 3.90 [3.25–4.56], and for BP it was having no history of hypertension 2.93 [2.74–3.12]. Second, participation in exCR was the strongest predictor for both outcomes 1.60 [0.83–2.37]; 1.50 [1.15–1.86]. For smoking abstinence, 5 organizational variables were identified as meaningful predictors, the strongest being prescription of varenicline by the centre physicians 1.98 [0.13–3.84] (Figure 2). The strongest patient-level predictors were exCR participation 2.51 [2.24–2.79] and socioeconomic status variables e.g., income 1.67 [1.28–2.06], living with partner 1.47 [0.84–2.09] and education 0.80 [0.48–1.12].

Conclusion
The study identified multiple CR organizational and patient-level predictors for reaching key risk factor targets one-year post-MI. The results might contribute to defining the optimal composition of comprehensive CR programmes.

Funding Acknowledgement
Type of funding sources: Public grant(s) – National budget only. Main funding source(s): 1) The Swedish Research Council for Health, Working Life and Welfare (FORTE)2) The Swedish Heart and Lung Foundation (Hjärt Lung Fonden)