Enfermedades cardiovasculares y diagnóstico

Effect of Systemic Arterial Blood Pressure on Fractional Flow Reserve

Abstract

Osman Kayapinar*, Cem Ozde, Gülşah Aktüre, Gökhan Coşkun and Adnan Kaya

Backgraund: Fractional flow reserve (FFR) measures the flow reserve of narrowed coronary arteries. It is calculated simply as the ratio of hyperemic distal coronary pressure (Pd) to aortic pressure (Pa) (Pd/Pa). We aimed to examine the relationship between arterial blood pressure normalization and FFR in hypertensive patients.

Methods: Twenty patients (14 males, 6 females; age 62.7±6.1 years) who underwent coronary angiography (CAG) with a diagnosis of stable coronary artery disease (CAD), and had 50–70% stenosis in their coronary arteries and a blood pressure higher than 140/90 mmHg in the catheter laboratory, were included in this study. The total number of lesions studied was 20. FFR was measured using a pressure measurement wire from Certus (St. Jude Medical, St. Paul, MN, USA). Measurements were made with 150 mcg adenosine in the left anterior descending (LAD) and circumflex (Cx) arteries and 100 mcg in the right coronary artery (RCA). A FFR <0.80 was considered significant in both measurements, which were repeated after blood pressure normalization with nitroglycerin infusion at 20 mcg/min. The difference between the measurements [nitrate (-), nitrate (+]) was analyzed.

Results: Of the 20 lesions evaluated, 1 was in the left main coronary artery, 9 in the LAD, 6 in the Cx, and 4 in the RCA) Systolic, diastolic and mean blood pressure decreased significantly after nitroglycerin infusion (p <0.0001). There was no significant difference between nitrate (-) and nitrate (+) in baseline FFR measurements (p <0.084). There was a significant difference between nitrate (-) and nitrate (+) patients in FFR measurements after hyperemia (p <0.005). In two patients with significant FFR measurements prior to nitrate, FFR lost its significance after a blood pressure decrease following nitrate infusion.

Conclusion: In hypertensive individuals, hyperemia-related FFR values are significantly increased after normalization of blood pressure. In the evaluation of moderate coronary lesions of hypertensive patients with FFR, decreasing the mean blood pressure to normal values may be important for preventing unnecessary interventions.