title: Safety and efficacy of a novel hyperaemic agent, intracoronary nicorandil, for invasive physiological assessments in the cardiac catheterization laboratory.
abstract: OBJECTIVE
  Maximal hyperaemia is a key element of invasive physiological studies and adenosine is the most commonly used agent. However, infusion of adenosine requires additional venous access and can cause chest discomfort, bronchial hyper-reactivity, and atrioventricular conduction block. The aim of this study was to evaluate the feasibility and efficacy of intracoronary (IC) nicorandil as a novel hyperaemic agent for invasive physiological studies.
  
  
  RESULTS
  We enrolled 210 patients who underwent fractional flow reserve (FFR) measurement. Hyperaemic efficacy of the following methods was compared: IC bolus injection of adenosine; intravenous (i.v.) infusion of adenosine (140 μg/kg/min); and IC bolus of nicorandil (1 and 2 mg). In 70 patients, the index of microcirculatory resistance was also measured. Hyperaemic efficacy of IC nicorandil 2 mg was non-inferior to that of i.v. adenosine infusion (FFR: 0.82 ± 0.10 vs. 0.82 ± 0.10; P for non-inferiority < 0.001). There was a strong correlation between FFRs measured by i.v. adenosine and IC nicorandil (R² = 0.934). Nicorandil produced fewer changes in blood pressure, heart rate and PR interval, and less chest pain than adenosine (all P-values < 0.05). Atrioventricular block occurred in 12 patients with IC adenosine, 4 patients with i.v. adenosine and none with IC nicorandil. The index of microcirculatory resistance was 18.3 ± 8.7 with i.v. adenosine and 17.2 ± 7.6 with IC nicorandil (P = 0.126).
  
  
  CONCLUSIONS
  This study suggests that IC bolus injection of nicorandil is a simple, safe, and effective way to induce steady-state hyperaemia for invasive physiological evaluations. Clinicaltrials.gov number: NCT01331902.
authors: Department of Internal Medicine and Cardiovascular Center, Seoul National University Hospital, 101 Daehang-ro, Chongno-gu 110-744 Seoul, Korea.
authors: Ho-Jun
authors: HJ
authors: Jang
authors: Bon-Kwon
authors: BK
authors: Koo
authors: Hee-Sun
authors: HS
authors: Lee
authors: Jun-Bean
authors: JB
authors: Park
authors: Ji-Hyun
authors: JH
authors: Kim
authors: Myung-Ki
authors: MK
authors: Seo
authors: Han-Mo
authors: HM
authors: Yang
authors: Kyung-Woo
authors: KW
authors: Park
authors: Chang-Wook
authors: CW
authors: Nam
authors: Joon-Hyung
authors: JH
authors: Doh
authors: Hyo-Soo
authors: HS
authors: Kim
mesh_terms: D000368:Aged; D006328:Cardiac Catheterization / Q000379:methods*; D017023:Coronary Angiography; D003324:Coronary Artery Disease / Q000503:physiopathology / Q000628:therapy*; D004333:Drug Administration Routes; D005240:Feasibility Studies; D005260:Female; D053805:Fractional Flow Reserve, Myocardial / Q000187:drug effects; D006439:Hemodynamics / Q000502:physiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D020108:Nicorandil / Q000008:administration & dosage* / Q000009:adverse effects; D011446:Prospective Studies; D016896:Treatment Outcome; D014665:Vasodilator Agents / Q000008:administration & dosage* / Q000009:adverse effects
chemical_list: D014665:Vasodilator Agents; D020108:Nicorandil
keywords: Fractional flow reserve; Hyperaemia; Nicorandil