Nitroprusiato: una droga confiable para la estimación de la reserva de flujo fraccional coronario

Abstract

Coronary angiography remains the gold standard for diagnosing coronary artery disease and making thera- peutic decisions. However the significance of interme- diate lesions (between 50-70%) is difficult to evalua- te. Fractional flow reserve (FFR) measurement is an important tool for the evaluation of these lesions. To achieve maximum vasodilatation, Intracoronary (IC) bolus or a continuous intravenous infusion of (A) is usually used. There is very little data for an alternative drug. The aim of this study was to evaluate Sodium nitroprusside (N) 50 µg IC bolus as an alternative to A for to determine FFR. Method and Results: A multicentric, randomi- zed clinical trial was conducted. A, (120 µg IC) and subsequently N (50 µg IC) or vice versa was used for every lesion. 60 coronary lesions were evaluated in 44 patients (24 men and 20 women), mean age 63.5 ± 9.6 years and BMI 28.95 ± 3.32 kg/m2. The lesions were located in the left anterior descending artery in 46.7% of patients, the right coronary in 26.7%, the circumflex in 11.7% and others in 13.9%. Mean coronary artery stenosis as assessed by quantitative coronary angiography (QCA) was 49.5% (95% CI: 46.5 - 52.5%).The mean arterial pressure (MAP) was similar in groups at baseline.(pre - A: 106.5 ± 18.2 mmHg, pre - N: 105.6 ± 18.8 mmHg, NS), or after A, but there was a transient decrease in MAP when N was administered (average decline of MAP: 12.5 mmHg, (95% CI: 9.2 to 15.7 mmHg, 2p < 0.001). This effect was due to the prolonged hypere- mia time achieved with the drug (hyperemia duration with nitroprusside 39.2 ± 8.7 sec. and with adenosine of 15.3 ± 3.2 sec. 2p < 0.001). We could demonstrate an excellent correlation between IC nitroprusside and IC adenosine with regard to FFR measurement, (corre- lation coefficient = 0.986, p < 0.001). Only one case of transient symptomatic hypotension with nitroprussi- de was observed. Angina developed in 4 patients with adenosine as against only 2 patients with nitroprussi- de. In addition, 10 patients developed symptomatic Atrio-ventricular block (AV block) with adenosine as against none with nitroprusside. Conclusion: IC bolus of nitroprusside is a safe and reliable alternative to induce hyperemia for FFR measurement. The more sustained vasodilatation and hyperemic response with nitroprusside can help to simplify the procedure and obviate the limitations seen with adenosine.