Primary prevention guidelines emphasize the importance of lifestyle modification, but many at high-risk have suboptimal cardiovascular risk factor (CVRF) control. Text message support may improve control, but the evidence is sparse. Our objective was to determine the impact of text messages on multiple CVRFs in a moderate-high risk primary prevention cohort.

This study was a single-blind randomized clinical trial comparing semi-personalized text message-based support to standard care. A random sample of adults with 10-year absolute cardiovascular risk score ≥10% and without coronary heart disease, referred from February 2019 to January 2020, were recruited from an outpatient cardiology clinic in a large tertiary hospital in Sydney, Australia. Patients were randomized 1:1 to intervention or control. Intervention participants received 4 texts per week over 6 months, and standard care, with content covering: diet, physical activity, smoking, general cardiovascular health, and medication adherence. Controls received standard care only. Content was semipersonalized (smoking status, vegetarian or not-vegetarian, physical ability, taking medications or not) and delivered randomly using automated software. The primary outcome was the difference in the proportion of patients who have ≥3 uncontrolled CVRFs (out of: low-density lipoprotein cholesterol >2.0 mmol/L, blood pressure >140/90 mm Hg, body mass index ≥25 kg/m², physical inactivity, current smoker) at 6 months adjusted for baseline. Secondary outcomes included differences in biomedical and behavioral CVRFs.

Among 295 eligible participants, 246 (mean age, 58.6 ± 10.7 years; 39.4% female) were randomized to intervention (n = 124) or control (n = 122). At 6 months, there was no significant difference in the proportion of patients with ≥3 uncontrolled CVRFs (adjusted relative risk [RR] 0.98; 95% confidence interval [CI] 0.75-1.29; P = .88). Intervention participants were less likely to be physically inactive (adjusted RR 0.72; 95% CI 0.57-0.92; P = .01), but there were no significant changes in other single CVRFs. More intervention participants reduced the number of uncontrolled CVRFs at 6-months from baseline than controls (86% vs 75%; RR 1.15; 95% CI 1.00-1.32; P = .04).

In moderate-high cardiovascular risk primary prevention, text message-based support did not significantly reduce the proportion of patients with ≥3 uncontrolled CVRFs. However, the program did motivate behavior change and significantly improved cardiovascular risk factor control overall. Larger multicenter studies are needed.