Secondary prevention through comprehensive cardiovascular rehabilitation: From knowledge to implementation. 2020 update. A position paper from the Secondary Prevention and Rehabilitation Section of the European Association of Preventive Cardiology

This is not a single experiment but a clinical practice guideline and position paper. The authors reviewed existing randomised controlled trials, meta-analyses, and observational studies to update the core components of cardiac rehabilitation (CR) for secondary prevention of cardiovascular disease. They tested no new intervention themselves. Instead, they synthesised evidence on:

**Exercise training modalities:** Continuous moderate-intensity training, high-intensity interval training (HIIT), resistance training, inspiratory muscle training, and combined approaches.

**Risk factor management:** Lipid control (LDL targets <1.4 mmol/L or <55 mg/dL), blood pressure targets (<130/80 mmHg in most patients), glycaemic control (HbA1c <7% for diabetics), smoking cessation, and weight management (waist circumference targets <94 cm for men, <80 cm for women).

**Psychosocial interventions:** Screening for depression, anxiety, and distress; stress management training; and referral pathways for mental health support.

**Patient education:** Structured programmes covering medication adherence, symptom recognition, dietary counselling (Mediterranean diet emphasis), and return-to-work guidance.

The "comparator" across the underlying studies was usual care (no structured rehabilitation) or less comprehensive rehabilitation programmes. Outcome measures included cardiovascular mortality, all-cause mortality, hospital readmission rates, exercise capacity (peak VO₂ in mL/kg/min), quality of life (various validated instruments), and modifiable risk factor levels.

The evidence base underpinning this position paper draws from hundreds of studies involving tens of thousands of patients. The paper itself does not report a single sample, but the populations covered include:

Patients after acute myocardial infarction (heart attack)

Patients after coronary artery bypass grafting (CABG) surgery

Patients after percutaneous coronary intervention (stenting)

Patients with stable angina, chronic heart failure (with reduced and preserved ejection fraction), peripheral artery disease, and after heart valve surgery or heart transplantation

Age range: predominantly 50–80 years old, though younger patients (post-MI in their 30s–40s) and older adults (>80) are included

Both sexes, though women remain underrepresented in CR trials (typically 20–30% of study populations)

Comorbid populations: diabetes (30–40%), hypertension (50–70%), obesity (30–50%), and depression (15–30%)

The paper explicitly notes that patients with frailty, cognitive impairment, or severe comorbidities are often excluded from trials, limiting generalisability to the sickest patients.

The paper does not report original measurements but defines standardised assessment tools for CR programmes:

**Exercise capacity:** Cardiopulmonary exercise testing (CPET) measuring peak VO₂ (mL/kg/min) — the gold standard. Where CPET unavailable, the 6-minute walk test (distance in metres) or symptom-limited treadmill/bike ergometry (METs achieved).

**Quality of life:** Disease-specific instruments like the MacNew Heart Disease Health-related Quality of Life questionnaire or generic tools like the SF-36 or EQ-5D.

**Depression screening:** Patient Health Questionnaire-9 (PHQ-9, 0–27 scale, ≥10 indicates moderate depression) or Hospital Anxiety and Depression Scale (HADS, 0–21 per subscale).

**Adherence:** Session attendance rates (percentage of prescribed sessions completed), medication adherence (Morisky Medication Adherence Scale, 0–8, higher = better), and dropout rates.

**Risk factor targets:** Blood pressure (office and ambulatory), LDL cholesterol (fasting lipid panel), HbA1c (glycated haemoglobin), waist circumference (cm), body mass index (kg/m²), and smoking status (self-report verified by exhaled CO or cotinine).

**Cardiac function:** Left ventricular ejection fraction (LVEF, % by echocardiography or MRI), and for heart failure patients, NT-proBNP levels (pg/mL).

**Study design:** This is a position paper — a consensus document from a professional society (European Association of Preventive Cardiology). It is not a systematic review or meta-analysis, though it cites meta-analyses and RCTs. The authors convened expert panels, reviewed literature published since the 2010 version, and reached consensus on updated recommendations. They used a structured approach: each core component (exercise, nutrition, psychosocial, etc.) was assigned to a writing group, then the full document was reviewed by the entire panel and externally by the EAPC board.

**Why this design matters:** Position papers are authoritative because they represent the collective judgment of experts who have weighed the entire evidence base. They are not subject to the biases of a single trial. However, they are also not as rigorous as a systematic review with pre-registered search strategies, explicit inclusion/exclusion criteria, and quality assessment of each study. The recommendations are graded (Class I, IIa, IIb, III) based on level of evidence (A, B, C), following standard ESC methodology. For example, "Exercise training is recommended for all cardiac patients" is Class I, Level A (strongest evidence from multiple RCTs or meta-analyses). "Routine use of inspiratory muscle training" is Class IIb, Level B (weaker evidence, may be considered).

**What this design can prove:** It can establish standard-of-care recommendations based on the best available evidence. It can identify gaps in knowledge and areas needing further research. It can provide practical implementation frameworks.

**What this design cannot prove:** It cannot prove causality — that's what the underlying RCTs do. It cannot quantify effect sizes with the precision of a meta-analysis. It cannot resolve contradictions between studies; instead, it reflects expert consensus on how to handle conflicting data. It is also vulnerable to groupthink and conflicts of interest (though the authors declare none relevant).

**Major methodological weaknesses:**

No systematic search strategy is reported (no PRISMA diagram, no search terms, no databases listed)

No formal quality assessment of included studies

No quantitative synthesis (no forest plots, no pooled effect sizes with confidence intervals)

The evidence base is heavily weighted toward white European men aged 50–70; generalisability to women, ethnic minorities, and very elderly patients is uncertain

Many recommendations are based on observational data or expert opinion (Level C evidence) rather than RCTs

The paper does not address cost-effectiveness in different healthcare systems, though it claims CR is "cost-effective"

**Primary outcomes (mortality and hospitalisation):**

Comprehensive CR reduces cardiovascular mortality by approximately 26% (relative risk reduction) compared to usual care, based on meta-analyses of RCTs (Cochrane review, 2016, ~6,000 patients)

All-cause mortality is reduced by roughly 13–20%

All-cause hospital readmissions are reduced by approximately 18% (relative risk reduction)

Myocardial infarction recurrence is reduced by about 17%

**Secondary outcomes (risk factors and function):**

Peak VO₂ improves by 10–25% (mean ~15%) after 8–12 weeks of supervised exercise training, translating to a gain of roughly 2–4 mL/kg/min

LDL cholesterol decreases by 10–20 mg/dL (0.3–0.5 mmol/L) when exercise is combined with dietary counselling and statin therapy optimisation

Systolic blood pressure drops by 5–10 mmHg on average

HbA1c in diabetic patients decreases by 0.3–0.5 percentage points

Depression scores (PHQ-9 or HADS) improve by 2–4 points, with clinically meaningful reductions in about 50% of patients with baseline depression

Smoking cessation rates at 12 months are 20–30% higher in CR programmes with dedicated smoking cessation counselling compared to usual care

Quality of life scores improve by 0.5–1.0 standard deviations (large effect) on disease-specific instruments

**Exercise modality-specific findings:**

HIIT (e.g., 4×4 minutes at 85–95% peak heart rate, 3×/week) produces larger improvements in peak VO₂ than moderate continuous training (MCT) — approximately 2–3 mL/kg/kg greater gain — but has higher dropout rates and requires careful patient selection (no arrhythmias, stable disease)

Resistance training (2–3×/week, 8–12 reps, 40–60% of 1-rep max) improves muscle strength by 20–40% and is safe in stable patients, but does not improve peak VO₂ as much as aerobic training

Inspiratory muscle training (30 breaths, 2×/day at 30% of maximal inspiratory pressure) improves respiratory muscle strength and dyspnoea in heart failure patients, but evidence for mortality reduction is lacking

**Implementation findings (the paper's main focus):**

Only 30–40% of eligible patients in Europe participate in CR after a cardiac event

Women are 20–30% less likely to be referred than men

Older adults (>75) and ethnic minorities are similarly under-referred

The median delay from hospital discharge to CR start is 4–6 weeks; delays >8 weeks are associated with 30% lower completion rates

Home-based or hybrid (centre + home) CR programmes show comparable outcomes to centre-based programmes in selected low-to-moderate risk patients, with adherence rates of 70–80% versus 60–70% for centre-based alone

To put these numbers in plain terms:

The 26% reduction in cardiovascular mortality means that if 100 people with heart disease receive usual care, roughly 8–10 will die from cardiovascular causes over the next 1–3 years. If those same 100 people complete comprehensive CR, that number drops to about 6–7. You need to treat roughly 25–30 patients to prevent one cardiovascular death.

The 18% reduction in hospital readmissions means that for every 100 patients, about 15–20 would be readmitted within a year with usual care; CR reduces that to about 12–16. Number needed to treat: roughly 20–25 to prevent one readmission.

The 15% improvement in peak VO₂ (2–4 mL/kg/min) is roughly equivalent to what a sedentary 60-year-old would gain from 6 months of regular brisk walking — it's the difference between being able to climb two flights of stairs without stopping versus needing a rest.

The 5–10 mmHg drop in systolic blood pressure is comparable to what you'd get from a standard-dose blood pressure medication (e.g., 10 mg lisinopril) — meaningful but not transformative on its own.

The 0.3–0.5 percentage point drop in HbA1c is modest — roughly equivalent to what you'd get from metformin — but when combined with other risk factor improvements, the cumulative effect is substantial.

**What the authors acknowledge:**

The evidence base is strongest for exercise and risk factor management, weaker for psychosocial interventions and patient education components

Many studies have short follow-up (6–12 months); long-term (>5 year) data are sparse

The optimal "dose" of exercise (frequency, intensity, duration) remains uncertain for specific subgroups

Home-based CR programmes lack standardisation and quality control

Implementation barriers (patient travel, work conflicts, lack of insurance coverage, physician inertia) are well-described but solutions remain understudied

The paper does not address digital health interventions (apps, wearables, tele-rehabilitation) in depth, though these were emerging at time of publication

**What a critical reader would note:**

The paper is a consensus document, not a systematic review — the authors may have selectively cited studies that support their views

Industry funding is declared as "none" for this paper, but many of the underlying studies were funded by pharmaceutical or device companies

The paper focuses almost exclusively on European healthcare systems; applicability to low- and middle-income countries is questionable

The "comprehensive" model of CR (all components delivered by a multidisciplinary team) is aspirational; most real-world programmes deliver only exercise and basic education

The paper does not address adverse events from exercise training (e.g., arrhythmias, myocardial infarction during HIIT) with sufficient detail — event rates are low (<1 per 10,000 patient-hours) but not zero

The recommendations for "new challenging populations" (heart failure with preserved ejection fraction, post-heart transplant, peripheral artery disease) are based on smaller, less robust studies

No discussion of sex-specific differences in response to exercise training, despite known differences in peak VO₂, body composition, and hormonal influences

The paper does not provide a clear framework for personalising CR intensity or duration based on baseline risk, frailty, or comorbidities — it's largely a one-size-fits-all approach

For someone running their own n=1 experiment to improve cardiovascular health after a cardiac event or to prevent one:

**What to test (specific intervention and dose):**

**Exercise:** A structured programme of 3–5 sessions per week, each 30–60 minutes. Include:

- Aerobic: 150 minutes/week of moderate-intensity (brisk walking, cycling, swimming — "talk but not sing" pace, roughly 60–75% of maximum heart rate) OR 75 minutes/week of vigorous-intensity (jogging, HIIT — "can't say more than a few words" pace, 80–90% max HR). HIIT example: 4 minutes hard, 3 minutes easy, repeat 4 times.

- Resistance: 2 sessions/week, 8–10 exercises targeting major muscle groups, 2–3 sets of 10–15 reps at moderate effort (you could do 2–3 more reps if pushed).

- Optional: Inspiratory muscle training (if you have heart failure or COPD) — 30 breaths twice daily using a threshold device set at 30% of your maximal inspiratory pressure.

**Diet:** Mediterranean-style eating — 5+ servings vegetables/day, 2+ servings fruit, whole grains, legumes, nuts, olive oil as primary fat, fish 2×/week, limited red meat and processed foods.

**Stress management:** 10–20 minutes/day of mindfulness, progressive muscle relaxation, or guided imagery.

**Smoking:** If you smoke, combine nicotine replacement therapy (patch + gum/lozenge) with behavioural support (counselling or app-based programme).

**Minimum meaningful duration:**

8–12 weeks is the minimum to see measurable improvements in peak VO₂ (10–15% gain) and blood pressure (5–10 mmHg drop)

6 months is needed for meaningful changes in body composition, HbA1c, and LDL cholesterol

12 months to see reductions in hospitalisation risk (though mortality benefits likely require sustained adherence)

For psychosocial benefits, 8–12 weeks of weekly sessions is typical

**What to measure (specific metrics):**

**Primary:** Peak VO₂ (if you have access to CPET) or 6-minute walk distance (self-administered on a flat, measured course — record metres walked in 6 minutes). Alternatively, track your resting heart rate and heart rate recovery (drop in HR 1 minute after stopping exercise — a faster drop indicates better fitness).

**Secondary:**

- Blood pressure (morning, seated, after 5 minutes rest — average of 3 readings)

- Fasting lipids (LDL, HDL, triglycerides) and HbA1c (every 3 months)

- Waist circumference (measured at navel level, after exhale)

- Body weight (weekly, same time of day)

- Quality of life: Use the EQ-5D-5L (free online) or a simple 0–10 scale for "how much does your heart condition limit your daily life?"

- Depression: PHQ-9 (free online, 9 questions, takes 2 minutes)

- Exercise adherence: Log sessions completed vs.