Non-invasive coronary flow velocity reserve assessment predicts adverse outcome in women with unstable angina without obstructive coronary artery stenosis.

Background: Evaluation of coronary flow velocity reserve (CFVR) is the physiological approach to assess the severity of coronary stenosis and microvascular dysfunction. Impaired CFVR occurs frequently in women with suspected or known coronary artery disease. The aim of this study was to assess the role of CFVR to predict long-term cardiovascular event rate in women with unstable angina (UA) without obstructive coronary artery stenosis. Methods: CFVR in left anterior descending coronary artery was assessed by adenosine transthoracic echocardiograhy in 161 women admitted at our Department with UA and without obstructive coronary artery disease. Results: During a mean FU of 32.5 ± 19.6 months, 53 cardiac events occurred: 6 nonfatal acute myocardial infarction, 22 UA, 7 coronary revascularization by percutaneous transluminal coronary angioplasty, 1 coronary bypass surgery, 3 ischemic stroke, and 8 episodes of congestive heart failure with preserved ejection fraction and 6 cardiac deaths. Using a ROC curve analysis, CFVR 2.14 was the best predictor of cardiac events and was considered as abnormal CFVR. Abnormal CFVR was associated with lower cardiac event-free survival (30 vs 80%, p < 0.0001). During FU, 70% of women with reduced CFVR had cardiac events whereas only 20% with normal CFVR (p = 0.0001). At multivariate Cox analysis, smoke habitus (p = 0.003), metabolic syndrome (p = 0.01), and CFVR (p < 0.0001) were significantly associated with cardiac events at FU. Conclusion: Noninvasive CFVR provides an independent predictor of cardiovascular prognosis information in women with UA without obstructive coronary artery disease whereas, impaired CFVR seems to be associated with higher CV events at FU.

Feasibility, symptoms, adverse effects, and complications associated with noninvasive assessment of coronary flow velocity reserve in women with suspected or known coronary artery disease.

BACKGROUND: Microvascular coronary impairment, defined as reduced coronary flow reserve, represents the predominant etiologic mechanism of ischemia in women with chest pain and no obstructive coronary artery disease. Transthoracic echocardiography (TTE) is a noninvasive method for assessing coronary flow velocity reserve (CFVR) in the left anterior descending coronary artery (LAD). The purpose of this investigation was to define the safety profile, feasibility, adverse events, and rate of complications of the test in women with suspected CAD. METHODS: We evaluated CFVR in LAD with TTE during adenosine infusion in 1455 women aged 66.4±11.9 years. RESULTS: A complete CFVR study was achieved in 1429 pts (feasibility 98.2%), the test being performed also in the early phase of acute coronary syndrome and on obese patients. Minor symptoms or adverse effects occurred in 43.7% of patients not requiring test termination: hyperpnea (16.7%), flushing (9.4%), atypical chest pain (9.9%), headache (6.6%), minor arrhythmias (2.9%), chest pain with EKG changes (1.5%) were the symptoms reported. No major complications were observed. CONCLUSIONS: Noninvasive assessment of CFVR in LAD by TTE is a very feasible method with very low incidence of adverse events and complications in women with suspected or known CAD. It is safe and can be used when evaluating female patients with atherosclerotic LAD disease or with coronary microvascular impairment.

Detection, location, and severity assessment of left anterior descending coronary artery stenoses by means of contrast-enhanced transthoracic harmonic echo Doppler.

AIMS: Contrast-enhanced second harmonic Doppler (ED) is a new ultrasound modality that increases the feasibility of recording blood flow velocity (BFV) in the left anterior descending coronary artery (LAD) using a transthoracic approach. Blood flow velocity convective acceleration is a reliable marker of coronary stenosis and can be used to assess the percentage area reduction at the stenosis site by applying the continuity equation. To detect, locate, and assess the severity of significant stenosis throughout the LAD by means of an ED recording of BFV acceleration at the stenosis site. METHODS AND RESULTS: Fifty-three consecutive patients undergoing coronary angiography (CA) underwent a colour-guided pulsed-wave ED recording of BFV in the proximal/mid and distal portions of the LAD, and maximal and reference BFV was obtained in each of the two arterial segments. Maximal velocity was much higher in the diseased segments (>or=50% lumen narrowing) than in the normal segments (143 +/- 84 vs. 38 +/- 20 cm/s; P < 0.001); as the reference velocity was similar (37 +/- 13 vs. 31 +/- 12; P = 0.03), the percentage increase in velocity was also higher (290 +/- 233 vs. 20 +/- 37%; P < 0.001). Using a cut-off value of an 82% increase in velocity, sensitivity and specificity vs. CA was, respectively, 86 and 95%. The reduction in the percentage area of stenosis calculated using the continuity equation agreed with that determined by means of quantitative CA (r = 0.7). CONCLUSION: Blood flow velocity evaluation in the LAD by means of transthoracic ED is feasible and reliable in detecting, locating, and assessing the severity of LAD stenosis.