Yoga and Cardiovascular Health Trial (YACHT): a UK-based randomised mechanistic study of a yoga intervention plus usual care versus usual care alone following an acute coronary event.

OBJECTIVE: To determine the effects of yoga practice on subclinical cardiovascular measures, risk factors and neuro-endocrine pathways in patients undergoing cardiac rehabilitation (CR) following acute coronary events. DESIGN: 3-month, two-arm (yoga +usual care vs usual care alone) parallel randomised mechanistic study. SETTING: One general hospital and two primary care CR centres in London. Assessments were conducted at Imperial College London. PARTICIPANTS: 80 participants, aged 35-80 years (68% men, 60% South Asian) referred to CR programmes 2012-2014. INTERVENTION: A certified yoga teacher conducted yoga classes which included exercises in stretching, breathing, healing imagery and deep relaxation. It was pre-specified that at least 18 yoga classes were attended for inclusion in analysis. Participants and partners in both groups were invited to attend weekly a 6- to 12-week local standard UK National Health Service CR programme. MAIN OUTCOME MEASURES: (i) Estimated left ventricular filling pressure (E/e'), (ii) distance walked, fatigue and breathlessness in a 6 min walk test, (iii) blood pressure, heart rate and estimated peak VO2 following a 3 min step-test. Effects on the hypothalamus-pituitary-adrenal axis, autonomic function, body fat, blood lipids and glucose, stress and general health were also explored. RESULTS: 25 participants in the yoga + usual care group and 35 participants in the usual care group completed the study. Following the 3-month intervention period, E/e' was not improved by yoga (E/e': between-group difference: yoga minus usual care:-0.40 (-1.38, 0.58). Exercise testing and secondary outcomes also showed no benefits of yoga. CONCLUSIONS: In this small UK-based randomised mechanistic study, with 60 completing participants (of whom 25 were in the yoga + usual care group), we found no discernible improvement associated with the addition of a structured 3-month yoga intervention to usual CR care in key cardiovascular and neuroendocrine measures shown to be responsive to yoga in previous mechanistic studies. TRIAL REGISTRATION NUMBER: NCT01597960; Pre-results.

Left-ventricular structure in the Southall And Brent REvisited (SABRE) study: explaining ethnic differences.

Cardiometabolic risk is elevated in South Asians and African Caribbeans compared with Europeans, yet whether this is associated with ethnic differences in left-ventricular structure is unclear. Conventional M-mode or 2-dimensional echocardiography may be misleading, because they calculate left-ventricular mass and remodeling using geometric assumptions. Left-ventricular structure was compared in a triethnic population-based cohort using conventional and 3-dimensional echocardiography on 895 individuals (aged 55-85 years; 427 European, 325 South Asian, 143 African Caribbean). Left-ventricular mass was indexed, and left-ventricle remodeling index and relative wall thickness were calculated. Anthropometry, blood pressure, and fasting bloods were measured. Three-dimensional left-ventricular mass index did not differ between Europeans (mean ± SE, 29.8 ± 0.3 g/m(2.7)) and African Caribbeans (29.9 ± 0.5 g/m(2.7); P=0.9), but it was significantly lower in South Asians (28.1 ± 0.4 g/m(2.7); P<0.0001) compared with Europeans. These findings persisted on multivariate adjustment. In contrast, conventional left-ventricle mass index was significantly higher in African Caribbeans (46.4 ± 0.9 g/m(2.7)) than in Europeans (41.9 ± 0.5 g/m(2.7); P<0.0001). Left-ventricle remodeling index was the highest in African Caribbeans and the lowest in South Asians. Relative wall thickness was also higher in African Caribbeans, but no different in South Asians, compared with Europeans. Differences in left-ventricle remodeling index were attenuated by adjustment for cardiometabolic factors between African Caribbeans and Europeans only. In conclusion, left-ventricular mass is lower in South Asians and equivalent in African Caribbeans compared with Europeans, even when cardiometabolic risk factors are accounted for. Left-ventricular remodeling rather than hypertrophy may explain the increased risk of heart failure in people of African Caribbean origin.