Coronary artery spasm and impaired myocardial perfusion in patients with ANOCA: Predictors from a multimodality study using stress CMR and acetylcholine testing

Background: We evaluated how comprehensive assessment of coronary artery lesions and their hemodynamic relevance by means of hybrid positron emission tomography (PET) and computed tomography (CT) imaging would affect decision-making in coronary artery bypass surgery (CABG), compared with using invasive coronary angiography (ICA) alone.Methods: After undergoing ICA, 27 patients (21 men and 6 women; mean SD age, 66 � 10 years) planned for cardiac surgery were scheduled for myocardial perfusion stress/rest evaluation with [13N]ammonia PET and CT coronary angiography. Only ICA was available to the surgeon. Postoperatively, the performed CABG was compared with the hypothetical strategy based on hybrid PET/CT findings (regional coronary flow reserve [CFR], myocardial perfusion defects). Procedures included CABG (n = 18) alone, CABG combined with valve replacement (n = 6), and CABG combined with isolated valve replacement (n = 3). A total of 56 bypass grafts (28 venous and 28 arterial) and 66 distal anastomoses were placed.Results: CT evaluation showed 93% concordance (66/71) with ICA regarding significant stenoses, with sensitivity, specificity, positive predictive value, and negative predictive value of 93.1%, 98.7%, 94.4%, and 98.4%, respectively. In the PET scan, 16 patients had 1 ischemic region, and 12 patients had 1 scar region, including 5 patients who presented with mixed conditions (scar and ischemia). One patient had a completely normal myocardium. Compared with the performed surgery, PET/CT fusion evaluation showed that of the performed anastomoses, 48% had documented ischemia (with a CFR <2 in 86%), 38% were nonischemic (although a CFR value <2 was found in 78%), and 14% had scar tissue (fixed perfusion defect).Conclusions: Although <50% of bypasses were placed to areas with myocardial ischemia, the CFR was low in the majority of nonischemic regions, a finding that may have important prognostic relevance. PET/CT fusion imaging could potentially influence planning for CABG and provide incremental prognostic information.

Download Full-text

Stress-induced Myocardial Ischaemia – Perfusion Contrast Echocardiography to Evaluate Presence and Severity of Coronary Artery Disease

European Cardiology Review ◽

10.15420/ecr.2011.7.3.172 ◽

2011 ◽

Vol 7 (3) ◽

pp. 172

Author(s):

Benoy Nalin Shah ◽

Roxy Senior ◽

◽

Keyword(s):

Coronary Artery Disease ◽

Coronary Artery ◽

Myocardial Perfusion ◽

Contrast Echocardiography ◽

Evidence Base ◽

Suspected Coronary Artery Disease ◽

Ultrasound Contrast Agents ◽

Prognostic Information ◽

Non Invasive ◽

Artery Disease

The development of stable transpulmonary ultrasound contrast agents (UCAs) has allowed the echocardiographic assessment of myocardial perfusion, a technique known as myocardial contrast echocardiography (MCE). MCE exploits the ultrasonic properties of UCAs, which consist of acoustically active gas-filled microspheres. These are intravascular agents that have a rheology similar to red blood cells and thus allow analysis of myocardial blood flow both at rest and after stress. The combined assessment of wall motion and myocardial perfusion provides significant diagnostic and prognostic information during stress echocardiography. Functional imaging tests, such as myocardial perfusion scintigraphy and stress cardiac magnetic resonance imaging, are also used for non-invasive assessment of coronary disease. The principal advantages of MCE are that it does not expose the patient to ionising radiation or radioactive pharmaceuticals, is not contraindicated in patients with an implanted metallic device or who suffer from claustrophobia and it can be performed at the bedside. The purpose of this article is to outline the physiological principles underpinning ischaemia testing with MCE before proceeding to review the evidence base for MCE in patients with known or suspected coronary artery disease.

Download Full-text