Year: 2014
Type: article
Abstract: Background: Despite the favourable effects of new therapeutic approaches during the acute phase of cardiac diseases and consequent favourable short-term outcomes, post-acute management and long term prognosis still remain unsatisfactory. Cardiac rehabilitation (CR) is a multidisciplinary treatment with established beneficial effects for the vast majority of cardiac patients and universally considered an important aspect of secondary prevention. Although it has been shown to reduce both morbidity and mortality and it is a class I recommendation in the guidelines, its use remains still rather limited in Europe and in the rest of the world. Aim: The aim of this PhD research was to examine some aspects still little known, or unknown at all, in this field. In particular, the research aimed to evaluate safety and efficacy of a structured, exercise-based, CR in specific cohorts of patients: after transcatheter aortic valve implantation (TAVI), after left ventricular assist device (LVAD) implantation, and early after an acute myocardial infarction (AMI) in high risk subjects. Methods: All patients (78 TAVI, mean age 82.1±3.6 years, 42 LVAD, 63.4 ± 7.4 years, and 376 AMI, 64.4±12.3 years) were referred to the Institute Codivilla-Putti (in Cortina d’Ampezzo, BL, Italy) for a two week, in-hospital, CR training and comprehensive risk factors interventions early after the acute event (within two weeks TAVI and AMI, within two months after LVAD implantation). TAVI patients were compared with 80 consecutive peer patients who were admitted for CR in the same period after surgical aortic valve replacement (sAVR) and LVAD patients compared with 47 coeval chronic heart failure (CHF) patients who were admitted for CR in the same period after an acute heart failure event. In LVAD cohort, cardiac autonomic function was evaluated by means of heart rate variability. AMI patients were divided into 2 groups according to a 40% left ventricular ejection fraction (LVEF) cut-off at enrolment, in order to evaluate the influence of a reduced LVEF on the rehabilitative process; furthermore, in 326 patients a glucometabolic characterization was obtained by means of a standard oral glucose tolerance test (OGTT) in patients without known diabetes. In all patients the training protocol consisted of a low-medium intensity exercise protocol developed in three sets of exercises, 6 days per week: 30 min of respiratory workout, followed by an aerobic session on a cyclette (or on an arm ergometer in those patients who were not able to cycle) in the morning and, in the afternoon, 30 min of callisthenic exercises. Each session was supervised by a physician and a physiotherapist and all patients were ECG monitored by a telemetry system. Functional capacity was assessed by a six min walking test (6MWT) on admission, and a second test at discharge; when possible, a cardiopulmonary exercise test (CPET) was also performed. The Barthel Index (BI) was used as an autonomy index in TAVI and LVAD cohorts. In AMI patients rate of death, hospitalizations, smoke cessation, physical activity and adherence to pharmacological treatment were recorded at follow up (up to 5 years, median 2 years). Results: Despite the high risk profile of the population, the drop out rate was quite low (1.3% of TAVI, 1.1% of AMI and 11.9% of LVAD patients had to be transferred due to non fatal complications). All the subjects who completed the program had enhanced independence, mobility and functional capacity (mean BI increment was 9.9±12.6, p<0.01 and 11.9±10.5, p<0.01, in TAVI and LVAD patients respectively; mean 6MWT gain was 60.4±46.4 mt, p<0.01, 83.2±36.0 mt, p<0.05, 70.7±55.7 mt, p<0.01, in TAVI, LVAD and AMI patients, respectively). Analysing the specific cohorts, a smaller proportion of TAVI patients, compared with sAVR, was able to complete at least a 6MWT (82% vs 92%) or a CPET (61% vs 95%) but, in those who did, the distance walked at 6MWT at discharge did not significantly differ between the groups (272.7±108 vs. 294.2±101 mt, p=0.42), neither did the exercise capacity assessed by CPET (peak-VO2 12.5±3.6 vs. 13.9±2.7 ml/kg/min, p=0.16). At the end of the program, physical performance in LVAD patients was still generally poor, but not dissimilar from that found in CHF patients (peak-VO2 reached at CPET was 12.5±3.0 vs. 13.6±2.9 ml/kg/min, p=0.20). Evaluating AMI patients, subjects with LVEF<40% achieved significantly lower peak-VO2 at CPET than the controls (15.2±3.9 vs. 18.2±5.2 ml/kg/min, p<0.01). After OGTT administration, a high prevalence of abnormal glucose metabolism was found (54%). As expected, exercise capacity was poorer in diabetic and pre-diabetic patients when compared with normoglicemic (peak-VO2 at CPET 15.3±4.1 vs 17.9±4.8 vs 19.4±5.5 ml/kg/min, p<0.01). At follow up 73% of the subjects reported to exercise regularly, 77% of the smokers definitively quitted and a high adherence to the therapy was registered. Cardiac and all cause mortality resulted 5.0% and 8.0 % at 1 year and 8.0 % and 13.0 % at 5 years, respectively and resulted higher in older people and in those with lower LVEF. Conclusions: Patients who underwent TAVI and LVAD implantation are characterized by a long-term deconditioning status. In this perspective, benefit is not automatically achieved through high-technology interventions and pharmacological management alone. This study have shown that a short-term, supervised, exercise-based CR is feasible, safe and effective in elderly patients after TAVI, as well as after traditional surgery, and after LVAD implantation. An early CR programme enhances independence, mobility and functional capacity and should be encouraged in these subjects. An early and intensive CR, based on physical activity and counselling, resulted to be safe and effective also in high risk patients after AMI, both in the short and in the long period. Indeed, a significant improvement in functional capacity in the short term - independent from the basal ventricular function or glucometabolic status - and a high adherence to therapy and to lifestyle modifications in the long term were achieved. Despite the high risk profile of these patients, this produced a favourable effect on cardiac and total mortality.
Authors: Nicola Russo, Sabino Iliceto, Fabio Bellotto
Language: English
Subfield: Cardiology and Cardiovascular Medicine
Field: Medicine
Domain: Health Sciences
Open Access status: green
OpenAlex ID: W148964665