Treadmill exercise test as a screening tool in the development of hypertension

Abstract Background Guidelines promote screening people with high normal BP for the presence of end-organ damage because their presence is associated with a 2- to 3-fold increase in the risk of CVD. Purpose Office blood pressure measurements may be unable to detect early subclinical cardiac damage of adverse prognostic significance in subjects with high normal blood pressure. Methods 100 consecutive subjects with high normal BP [systolic BP=130-139mmHg and/or diastolic BP=85-89mmHg] were examined for early signs of hypertension-mediated organ damage (HMOD). They underwent an echocardiographic study, a negative for ischemia treadmill exercise test (Bruce protocol) where the index SBP/MET-slope [(peak SBP—resting SBP)/(peakMET-1)] was used. Arterial stiffness was evaluated based on carotid-femoral pulse wave velocity (PWV). The sympathetic drive was assessed by MSNA. Follow-up was scheduled every 6 months for 3 consecutive years, where BP measurements were assessed in the office and with ambulatory BP monitoring (ABPM). All participants offered lifestyle advice to lower their BP. The endpoint was the development of HTN either with Office BP or ABPM. Results Of 100 subjects (54±8 years, 42 males, baseline office BP: 132/82 mmHg, 24-hour BP: 122/76 mmHg), 40 developed HTN in 3 years. 34 subjects developed Hypertensive Response to Exercise (HRE) (BP >210mmHg in men and >190mmHg in women) and all of them developed HTN. The SBP/MET-slope in future hypertensives was increased in all stages till peak exercise independently of sex type (stage1: 6.7vs4.9 p=0.049, stage2: 8.4vs4.8 p=0.001, peak: 6.7vs4.9, p=0.001). Their exercise capacity was reduced (10vs11.3METs, p=0.002) as well as their maximum exercise heart rate (156vs164, p=<0.0001). Those with HRE had higher 24hSBP (124vs121mmHg, p=0.009), Night SBP (117vs111mmHg, p<0.001), Day SBP (127vs124mmHg, p=0.012) Office Pulse Pressure (51vs47mmHg, p=0.01). Additionally, they had increased PWV (8.3vs7.5m/sec, p=<0.0001), MSNA levels (36vs28 bursts, p=<0.0001), LVMI (38vs34 gr/m2.7, p=0.02), and a statistically significant deterioration of 2021 CKD-EPI eGFR (90 vs 97 mL/min/1.73 m², p=0.02). All of them correlated with development of hypertension (p=0.002), while they did not differ regarding their metabolic profile at the follow-up. Conclusion Detecting exaggerated blood pressure response and specifically an increased SBP/MET-slope in the end of second stage of Bruce protocol at treadmill exercise test is associated with increased systemic vascular resistance and early subclinical HMOD which may upgrade an individual’s cardiovascular disease (CVD) risk as they progress to HTN indicating a need for instituting a BP-lowering strategy.