Assessment of coronary vasomotor responses to acetylcholine in German and Japanese patients with epicardial coronary spasm-more similarities than differences?

Coronary spasm is an established cause for angina pectoris. Ethnic differences have been suggested among Asian compared to Caucasian patients regarding prevalence, gender distribution, and angiographic patterns of coronary spasm. The aim of this study was to compare contemporary German and Japanese patients with coronary spasm. Between 2011 and 2015, 149 patients with resting angina and unobstructed coronary arteries with acetylcholine-induced epicardial spasm were enrolled in Stuttgart, Germany (n = 69) and Sendai, Japan (n = 80). All patients underwent intracoronary acetylcholine testing according to a standardized protocol. Comprehensive analysis included type of spasm (focal/diffuse), dose of acetylcholine leading to spasm, and frequency of multivessel spasm. Patients in this study were 61 ± 11 years old, predominantly female (54%), and had normal left ventricular ejection fraction (73 ± 9%). Diffuse spasm was the most prevalent type of spasm (85%) whereas focal spasm was found in the remaining 15% of patients. 31% of patients had multivessel spasm. Comparing the German with the Japanese patients, distribution of spasm type (focal/diffuse, p = 0.19) and frequency of multivessel spasm (p = 0.22) were comparable. Moreover, when Japanese patients were compared with German patients and diffuse spasm with focal spasm patients, respectively, no significant differences were observed regarding the acetylcholine dose required to induce spasm (p = 0.078 and p = 0.46, respectively). In conclusion, diffuse epicardial coronary spasm is the most frequent finding among German and Japanese patients with resting angina, unobstructed coronary arteries, and epicardial spasm on acetylcholine testing. Japanese and German patients share several similarities including comparable types of spasm and frequency of multivessel spasm.

Impact of baseline calibration on semiquantitative assessment of myocardial perfusion reserve by adenosine stress MRI.

In this study, we sought to investigate the impact of baseline calibration, which is used in quantitative cardiac MRI perfusion analysis to correct for surface coil inhomogeneity and noise, on myocardial perfusion reserve index (MPRI) and its contribution to previously reported paradoxical low MPRI < 1.0 in patients with unobstructed coronary arteries. Semiquantitative perfusion analysis was performed in 20 patients with unobstructed coronary arteries undergoing stress/rest perfusion CMR and in ten patients undergoing paired rest perfusion CMR. The following baseline calibration settings were compared: (1) baseline division, (2) baseline subtraction and (3) no baseline calibration. In uncalibrated analysis, we observed ~ 20% segmental dispersion of signal intensity (SI)-over-time curves. Both baseline subtraction and baseline division reduced relative dispersion of t0-SI (p < 0.001), but only baseline division corrected for dispersion of peak-SI and maximum upslope also (p < 0.001). In the assessment of perfusion indices, however, baseline division resulted in paradoxical low MPRI (1.01 ± 0.23 vs. 1.63 ± 0.38, p < 0.001) and rest perfusion index (RPI 0.54 ± 0.07 vs. 0.94 ± 0.12, p < 0.001), respectively. This was due to a reversed ratio of blood-pool and myocardial baseline-SI before the second perfusion study caused by circulating contrast agent from the first injection. In conclusion, baseline division reliably corrects for inhomogeneity of the surface coil sensitivity profile facilitating comparisons of regional myocardial perfusion during hyperemia or at rest. However, in the assessment of MPRI, baseline division can lead to paradoxical low results (even MPRI < 1.0 in patients with unobstructed coronary arteries) potentially mimicking severely impaired perfusion reserve. Thus, in the assessment of MPRI we propose to waive baseline calibration.

Fractional flow reserve or optical coherence tomography guidance to revascularize intermediate coronary stenosis using angioplasty (FORZA) trial: study protocol for a randomized controlled trial.

BACKGROUND: The management of patients with angiographically intermediate coronary lesions is a major clinical issue. Fractional flow reserve provides validated functional insights while optical coherence tomography provides high resolution anatomic imaging. Both techniques may be applied to guide management in case of angiographically intermediate coronary lesions. Moreover, these techniques may be used to optimize the result of percutaneous coronary intervention. We aim to compare the clinical and economic impact of fractional flow reserve versus optical coherence tomography guidance in patients with angiographically intermediate coronary lesions. METHODS/DESIGN: Patients with at least one angiographically intermediate coronary lesion will be randomized (ratio 1:1) to fractional flow reserve or optical coherence tomography guidance. In the fractional flow reserve arm, percutaneous coronary intervention will be performed if fractional flow reserve value is ≤0.80, and will be conducted with the aim of achieving a post-percutaneous coronary intervention fractional flow reserve target value of ≥0.90. In the optical coherence tomography arm, percutaneous coronary intervention will be performed if percentage of area stenosis (AS%) is ≥75% or 50 to 75% with minimal lumen area <2.5 mm2, or if a major plaque ulceration is detected. In case of percutaneous coronary intervention, optical coherence tomography will guide the procedure in order to minimize under-expansion, malapposition, and edge dissections.Cost load and clinical outcome will be prospectively assessed at one and thirteen months. The assessed clinical outcome measures will be: major cardiovascular events and occurrence of significant angina defined as a Seattle Angina Questionnaire score <90 in the angina frequency scale. DISCUSSION: The FORZA trial will provide useful guidance for the management of patients with coronary artery disease by prospectively assessing the use of two techniques representing the gold standard for functional and anatomical definition of coronary plaques. TRIAL REGISTRATION: Clinicaltrials.gov NCT01824030.