Lifestyle Practices, Symptom Control, and Health-Related Quality of Life in Cardiovascular Care: An Explanatory Sequential Mixed-Methods Study

Background Health-promoting lifestyle modification is essential for cardiovascular disease (CVD) secondary prevention; however, behavioral and contextual influences on patient outcomes remain insufficiently explored in South Asian settings. This study examined associations between lifestyle practices, symptom control, and health-related quality of life (HRQoL) among cardiac patients in Puducherry, India, and explored contextual factors influencing these outcomes. Methods An explanatory sequential mixed-methods design (QUAN → qual) was conducted at a tertiary teaching hospital. The quantitative phase included 162 adults aged 18–59 years with cardiovascular conditions. Data were collected using the Health-Promoting Lifestyle Profile II (HPLP-II), Seattle Angina Questionnaire-7 (SAQ-7; n = 140), and WHOQOL-BREF. The qualitative phase involved semi-structured interviews with 16 purposively selected participants with good (n = 8) and poor (n = 8) symptom control. Data were analyzed using Braun and Clarke’s six-phase thematic analysis. Results Overall, 62.3% demonstrated fair or needs-improvement lifestyle practices (mean HPLP-II: 2.46 ± 0.29). Mean SAQ-7 and WHOQOL-BREF scores were 53.92 ± 21.88 and 58.73 ± 9.45, respectively. Lifestyle practices correlated positively with symptom control (r = 0.228, p = 0.007) and HRQoL (r = 0.415, p < 0.001). Regression analysis explained 34.0% of HRQoL variance. Lifestyle practices, marital status, and illness duration exceeding five years were independently associated with HRQoL. Eight qualitative themes highlighted emotional adjustment, self-management, medication adherence, family support, and financial and occupational challenges. Discussion and Conclusion Health-promoting lifestyle practices were suboptimal among cardiac patients and were positively associated with both symptom control and HRQoL. Lifestyle practices, marital status, and longer illness duration were independently associated with HRQoL, while qualitative findings highlighted the influence of occupational demands, financial constraints, medication adherence, and family support on patients’ self-management experiences. These findings underscore the need for comprehensive secondary prevention strategies integrating structured nurse-led lifestyle counseling, family-centered support, and interventions addressing socioeconomic barriers.