The proper care for elderly cardiac patients before rehabilitation Free

Cardiovascular diseases are still a main cause of mortality across the world. Numerous studies and meta-analyses have demonstrated the benefits of cardiac rehabilitation on hard clinical outcomes, including cardiovascular and all-cause mortality.^1,2 Even in patients aged 75 years and older cardiac rehabilitation improves functional parameters (such as peak oxygen consumption, distance walked in 6 min and inferior limbs peak 90° torque strength) and quality of life (QoL), as shown in the CR-AGE EXTRA study.³

Exercise capacity was proved to be a strong predictor of mortality.⁴ This holds true also for elderly patients enrolled in cardiac rehabilitation programmes after an episode of heart failure decompensation – the physical activity scale for the elderly was shown to be a strong and independent predictor of mortality.⁵

Quantifying exercise limitation and its impact on lifestyle also has a value in establishing diagnosis and prognosis. To find the main predictors of pre-rehabilitation exercise capacity in elderly patients appears to have an impact in future improvement of managing these patients.

The European study on effectiveness and sustainability of current cardiac rehabilitation programmes in the elderly (EU-CaRE) study is a prospective study comparing data and predictors of exercise capacity of patients undergoing cardiac rehabilitation in eight centres across Western Europe. Consecutive patients with ischaemic heart disease and heart valve replacement were included. PeakVO₂ was assessed by cardiopulmonary exercise test.⁶

Only two large studies have posed the question about the predictors of pre-rehabilitation exercise capacity in the elderly. In the largest cohort of patients with extremely low values of peak VO₂ on entry to cardiac rehabilitation it was concluded, as in this study, that the main influence is heart failure with low ejection fraction.⁷ The prevalence of cardiac risk factors was 62% for hypertension, 78% for overweight (body mass index (BMI) > 25 kg/m²) and 40% for obesity (BMI > 30 kg/m²). At all ages and in both men and women, patients who underwent coronary artery bypass graft (CABG) surgery had lower age-adjusted values of peak VO₂.

In another large study sex, age, BMI, New York Heart Association (NYHA) class, resting and peak heart rate, beta blocker and fasting blood glucose⁸ were found to be significant predictors. There are other studies with specific criteria found to be significantly influencing rehabilitation. In patients with class II–III heart failure and left ventricular systolic dysfunction, the main echocardiographic predictors of exercise capacity are related to the presence of significant mitral regurgitation.⁹

What is of great importance in this study is the fact that it is the first to identify the most important predictors for exercise capacity in a large cohort of elderly coronary artery disease (CAD) and/or valvular heart disease patients. Determinants of peak VO₂ among 1582 patients were found to be age, CABG, valve surgery, heart failure with reduced ejection fraction, nephropathy and peripheral artery disease.

An important finding in the current study was that haemoglobin is strongly associated with peak VO₂. Only few prior studies have reported a relationship between exercise capacity and haemoglobin values in cardiac patients.^10,11 While the role of haemoglobin in heart failure and renal disease has been investigated, little is known about its effect on clinical exercise test performance and mortality in patients referred for cardiac rehabilitation programmes. Anaemia is independently associated with increased mortality and hospitalizations in patients with both heart failure with reduced ejection fraction (HFrEF) and heart failure with preserved ejection fraction.¹² Early data from short-term studies in patients with HFrEF and absolute or functional iron deficiency with or without anaemia suggest that intravenous but not oral iron therapy may have a potential role in improving exercise capacity, NYHA class and QoL.^13,–15 Another proof of the relationship found in the EU-CaRE study is a publication which concluded that anaemic patients (haemoglobin < 13 g/dL) achieved lower metabolic equivalents than non-anaemic patients and had more ST-segment depression (15.5% vs. 8.6%, p < 0.004).¹⁶

The link between age, heart failure, ejection fraction, forced expiratory volume in the first second and exercise capacity has been well established in previous similar studies. Other not well-studied comorbidities with strong association with future rehabilitation were found here: nephropathy, peripheral arterial disease, atrial fibrillation, diabetes mellitus, obesity and inactivity. The addition of each comorbidity or cardiovascular risk factor was associated with a decrease of 1.7 and 1.1 mL/kg per min, respectively.

An indisputable benefit of the study is the age range. Due to population aging, it is becoming more and more important to know better what elderly people suffer from. Patients with multiple chronic conditions have on average a higher level of morbidity, as already proved, as well as poorer physical functioning and quality of life, a greater likelihood of persistent depression, and lower levels of social wellbeing.¹⁷

A certain limitation of the study is the fact that, due to the explorative nature, the results explained only 52% of the total variance in peak VO₂, leaving a considerable part unexplained (as the authors themselves stated in their Conclusion).

Nevertheless, we consider the recent study as contributing to the current understanding and treating of this increasing population of old people with chronic cardiac and valvular disease. Knowing which are the most important predictors of exercise capacity in elderly CAD patients could answer arising questions concerning which diseases and conditions need closer follow-up. The results from the study could form a groundwork from which to create a reference database that could be used both in clinical practice to initiate a rehabilitation of such patients and in future studies evaluating different interventions. Treating better the comorbidities found as strong predictors could be the key for better rehabilitation in these elder patients. An important conclusion is the necessity of routine haemoglobin measurement in elderly patients.

Declaration of conflicting interests

The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Funding

The author(s) received no financial support for the research, authorship, and/or publication of this article.

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