Low diastolic blood pressure is associated with a high atherosclerotic burden in patients with obstructive coronary artery disease.

Background: The optimal blood pressure (BP) treatment target is still being debated, specifically di-astolic BP (DBP) in patients with obstructive coronary artery disease (CAD); a DBP which is too low could compromise myocardial perfusion and is associated with adverse outcomes.
Methods: This study examined the relationship between DBP levels and the severity and atheroscle-rotic burden of CAD in 231 consecutive stable patients with evidence of obstructive CAD as detected by elective coronary angiography. The SYNTAX (Synergy Between Percutaneous Coronary Intervention With Taxus and Cardiac Surgery) Score and SYNTAX Score II were used to quantify the atherosclerotic burden.
Results: The patients were male (71%), median age 62, interquartile range [IQR] of 57 to 67, and 84% had hypertension. The median DBP was 71.0 mmHg (IQR: 61 to 80) and the median SYNTAX Score was 16.0 (IQR 9.0-23.0). DBP levels were inversely correlated with SYNTAX Score (r = -0.61) and SYNTAX Score II (r = -0.73). Adjusting for traditional risk factors, unprotected left main CAD, systolic BP, renal function, and medications, DBP levels remained independently inversely associated with a higher tertile of SYNTAX Score (adjusted odds ratio [OR] 0.89; 95% confidence interval [CI] 0.85-0.92, p < 0.001) and SYNTAX Score II (adjusted OR 0.75; 95% CI 0.69-0.80, p < 0.001). The frequency of high athero-sclerotic burden identified by the presence of intermediate or high SYNTAX Score and SYNTAX Score II was significantly higher among patients with a DBP < 60 mmHg.
Conclusions: Low DBP levels are independently associated with high SYNTAX Score and SYNTAX Score II in stable patients with obstructive CAD.