Feasibility study to assess the delivery of a novel isometric exercise intervention for people with high blood pressure in a healthcare setting

BACKGROUNDHypertension affects 1 in 4 adults and increases the risk of CV disease. Management aims to reduce blood pressure to a level that minimises risk; however, up to 50% of people fail to achieve blood pressure targets often due to insufficient treatment or poor adherence. Exercise has a role to play in the management of hypertension. The impact of isometric exercise on hypertension in healthcare settings is poorly understood. METHODSRandomized controlled open label multicentre feasibility study of isometric exercise compared to standard care in unmedicated hypertensives. Participants received an individualized isometric wall squat prescription and performed 4 x 2-minute bouts thrice weekly for 6-months. We assessed recruitment, deliverability, attrition, adherence, and variance in blood pressure change. RESULTS41 participants (56 +/- 15 years), 59% women, were randomized. Isometric exercise was found to be easily deliverable to all participants. At 6-months 34% withdrew, of those who completed isometric exercise 87% of their sessions were at the correct intensity. Variance in blood pressure change was 14.4 mmHg. The study was not powered to show a difference in blood pressure between groups, however blood pressure reductions were seen in the intervention group at all study time points compared to baseline. CONCLUSIONSThe results have allowed us to calculate a sample size (n=542) for a full randomised controlled trial. The results demonstrate good acceptability and adherence rates to the treatment protocol. Our results show a signal towards a consistent systolic blood pressure reduction in the isometric exercise group compared to baseline. REGISTRATIONTrial number: NCT04936022 https://classic.clinicaltrials.gov/ct2/show/NCT04936022?cond=isometric+exercise&draw=2&rank=7 Registry IdentifierISRCTN 13472393