Blood pressure response during treadmill exercise testing and the risk for future cardiovascular events and new-onset hypertension

Background: Although there is a diminishing role of exercise stress testing (EST) in the diagnostic assessment of coronary heart disease, the physiologic response to exercise may provide valuable prognostic information. We aimed to investigate the association of repeated blood pressure (BP) measurements during EST with long-term risk of myocardial infarction, stroke or death (MACE), as well as the development of new-onset hypertension.

Methods: Retrospective analysis of EST performed between the years 2005-2019 in a single center according to Bruce protocol. Included were patients aged 35-75 years without a history of cardiovascular disease (n=14,792; 48% women). BP was documented at rest, submaximal exercise (Bruce stage-2), peak exercise and recovery (2 minutes). Association of BP measures with study outcomes during a median follow-up of 78 months was investigated.

Results: An increment of 10-mmHg in rest, submaximal, peak and recovery systolic BP was each associated with a significant increase in the hazard ratio (HR) and 95% confidence interval (CI) for MACE: 1.09 (1.04-1.14), 1.06 (1.01-1.10), 1.04 (1.01-1.08), and 1.06 (1.02-1.10), respectively, after adjustment including exercise capacity, medications and resting BP. The association between SBP at submaximal exercise and recovery with MACE had a J-shaped appearance (Figure). Among non-hypertensive patients without BP lowering medications (n=8,529), 13% were diagnosed with new-onset hypertension during follow-up. Excessive systolic BP response to peak exercise (≥190 mmHg in women and ≥210 mmHg in men) was an independent predictor of future hypertension [HR (95% CI)]: 1.87 (1.41-2.48), as were systolic BPs during submaximal exercise [>160 vs. ≤130 mmHg: 2.44 (1.97-3.03)] and recovery [≥140 vs. ≤120 mmHg: 1.65 (1.37-1.98)], showing gradual, incremental association with the risk for developing hypertension.

Conclusions: BP measurement during exercise and recovery phases of treadmill testing provides incremental prognostic information regarding long-term risk for cardiovascular events and the probability for developing future hypertension.