The Association of Morning Surge and Night-Time Dipping Blood Pressure with Significant and Complex Coronary Artery Lesions

Introduction: Hypertension responsible for more than 10 million deaths annually worldwide and abnormal diurnal blood pressure (BP) variation is associated with cardiovascular events. Aim: This study aimed to investigate the association between the 24-h ambulatory night BP dipping and morning BP surge (MS) with characteristic of coronary artery lesions that may contribute cardiovascular events and mortality burden. Methods: A cross sectional study over 1-year, collected 263 cases of hypertensive (80%) and non-hypertensive patients, aged 61 ± 10 years, who undergoing invasive coronary angiography (CAG) and 24-h ambulatory BP monitoring admitted to cardiology department complain of chest pain. The night-time/day-time dip and sleep-trough MS were calculated. Non-dipper status was considered when night-time/day-time dip < 10%, and significant coronary lesion (SCL) when ≥ 50 % stenosis in 1.5 mm vessels. The SYNTAX (Synergy Between Percutaneous Coronary Intervention with Taxus and Cardiac Surgery) score was used to quantify the complexity of SCL. Result: The mean morning systolic BP (SBP) surge was higher in the high SYNTAX Score subgroup than low and intermediate subgroups (25 ± 11 vs 17 ± 13 and 10 ± 10 mmHg, p < 0.010). Non-dipper SBP status was more frequently in patients with SCL than non-SCL (p < 0.019). In ordinal regression, hypertension was independent predictor of SCL (odd ratio: 0.40, p < 0.003), the night-time/day-time BP dip was independent predictor of being in a higher SYNTAX score subgroup (systolic odd ratio: 0.88, diastolic odd ratio: 1.14 p < 0.05). Conclusion: Hypertension is associated with SCL and the night-time/day-time BP dip as a continuous variable is associated with complex coronary lesion. Non-dipping as categorical variable and morning BP surge were not independent predictors of significant or complex coronary lesions.