Functional Versus Anatomic Imaging of CAD: Lessons Learned from Recent Clinical Trials

Comparing Cardiac Magnetic Resonance-Guided Versus Angiography-Guided Treatment of Patients With Stable Coronary Artery Disease: Results From a Prospective Randomized Controlled Trial

OBJECTIVES

The purpose of this study was the prospective and randomized evaluation of cardiovascular endpoints and quality of life in patients with stable coronary artery disease comparing a cardiac magnetic resonance (CMR)-based management strategy with a coronary angiography-based approach.

BACKGROUND

Evidence from trials prospectively evaluating the role of CMR in clinical pathways and decision processes is limited.

METHODS

Patients with symptomatic CAD were randomized to diagnostic coronary angiography (group 1) or adenosine stress CMR (group 2). The primary endpoint was the composite of cardiac death and nonfatal myocardial infarction. Quality of life was assessed using the Seattle Angina Questionnaire at baseline and during follow-up.

RESULTS

Two hundred patients were enrolled. In group 1, 45 revascularizations (45.9%) were performed. In group 2, 27 patients (28.1%) were referred to revascularization because of ischemia on CMR. At 12-month follow-up, 7 primary events occurred: 3 in group 1 (event rate 3.1%) and 4 in group 2 (event rate 4.2%), with no statistically significant difference (p = 0.72). Within the next 2 years, 6 additional events could be observed, giving 4 events in group 1 and 9 events in group 2 (event rate 4.1% vs. 9.4%; p = 0.25). Group 2 showed significant quality-of-life improvement after 1 year in comparison to group 1.

CONCLUSIONS

A CMR-based management strategy for patients with stable coronary artery disease was safe, reduced revascularization procedures, and resulted in better quality of life at 12-month follow-up, though noninferiority could not be proved. Optimal timing for reassessment remains to be investigated. (Magnetic Resonance Adenosine Perfusion Imaging as Gatekeeper of Invasive Coronary Intervention [MAGnet]; NCT02580851).

A patient-specific approach to assessing blood pressure management in patients with hypertension and coronary artery disease

The objective was to improve the management of patients with hypertension (HTN) and coronary artery disease (CAD), utilizing a model which integrates 3 determinants of coronary blood flow (CBF)-CAD severity, diastolic blood pressure (DBP), and left ventricular (LV) mass. We validated non-parametric equations for CBF estimation in a consecutive patient sample (N = 81) with HTN and CAD. There was a highly significant correlation (r = .565; P < .01) between clinical DBP and estimated CBF. Greater LV mass and more severe CAD shifted the relationship towards less CBF at the same DBP. LV mass was more critical when DBP >70 mm Hg. Estimated changes in CBF at different DBP considering the severity of CAD and LV mass can be calculated. In summary, the severity of CAD from coronary CT or coronary angiography combined with LV mass from echocardiography permits clinicians to guide the extent of, or target for, DBP to avoid seriously compromising CBF.

Prediction of fractional flow reserve with angiographic DILEMMA score

Objective:

Angiographic assessment of stenosis has limited predictive value for functionally significant lesions compared with fractional flow reserve (FFR). The recently developed angiographic DILEMMA score, which consists of minimal lumen diameter (MLD), lesion length (LL) and Bypass Angioplasty Revascularization Investigation (BARI) Myocardial Jeopardy Index (MJI) was found to have diagnostic value in predicting FFR ≤0.80. The present study was an investigation of prediction of FFR ≤0.80 using DILEMMA score and its relationship to resting distal coronary artery pressure/aortic pressure (Pd/Pa).

Methods:

Records of consecutive patients who underwent coronary angiography and FFR were retrospectively analyzed. Assessment of MLD and LL was performed using quantitative coronary angiography. BARI MJI was calculated using angiographic calculation index.

Results:

A total of 185 pressure wire analysis data sets from 150 patients were analyzed retrospectively. There were 82 lesions in FFR >0.80 group and 103 lesions in FFR ≤0.80 group. Negative correlation was found between FFR and DILEMMA score (r=-0.494; p<0.001), FFR and BARI-MJI (r=-0.378; p<0.001), and between FFR and LL (r=-0.314; p<0.001). Positive correlation was found between FFR and baseline Pd/Pa (r=0.713; p<0.001), and between FFR and MLD (r=0.415; p<0.001). DILEMMA score had negative correlation with resting Pd/Pa (r=-0.389; p<0.001). In receiver operating characteristic analysis for diagnosing FFR≤0.80, area under curve values of resting Pd/Pa, DILEMMA score, MLD, BARI-MJI, and LL were 0.862, 0.793, 0.780, 0.728, and 0.686, respectively.

Conclusion:

DILEMMA score had moderately strong correlation with FFR and good accuracy in diagnosing significant FFR, but it had weak correlation with resting Pd/Pa. (Anatol J Cardiol 2017; 17: 285-92)