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

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.

Characteristics of coronary flow velocity reserve on transthoracic Doppler echocardiography in patients with a history of Kawasaki disease

Whether the acute inflammation caused by Kawasaki disease will have an effect on the endothelial function of coronary arteries in the future is unknown.

METHODS

The coronary flow velocity reserve of the left anterior descending artery was examined by transthoracic Doppler echocardiography in 189 patients (male 125, female 64) with a history of Kawasaki disease and 10 volunteers (control). Their ages ranged from 6 to 40 years (median 22 years). The patients were divided into nine groups based on the left anterior descending artery lesions. The coronary flow velocity reserve was measured by intravenous administration of adenosine triphosphate (0.15 mg/kg/minute) while fasting. The coronary flow velocity reserve was calculated as the ratio of hyperaemic to basal mean diastolic flow velocities. The respective groups were as follows: control, no coronary artery lesions (n = 39), no coronary artery lesions in the right coronary artery (n = 29), regression (n = 11), aneurysm at the bifurcation of the left coronary artery (n = 26), aneurysm of the left anterior descending artery (n = 15), localised stenosis <75% (n = 12), localised stenosis ≥75% (n = 17), segmental stenosis (n = 5) and coronary artery bypass grafting (n = 36). One-factor ANOVA followed by Tukey's test was used to compare the coronary flow velocity reserve among the groups.

RESULTS

The coronary flow velocity reserve was significantly lower in the localised stenosis ≥75%, segmental stenosis and coronary artery grafting groups than in the other groups (p < 0.05).

CONCLUSIONS

The endothelial function in the epicoronary artery was preserved in patients with a history of Kawasaki disease and dilated coronary artery lesions.

Should we routinely assess coronary artery Doppler in daily echocardiography practice?

A lot of people with coronary artery disease do not have specific symptoms, and myocardial infarction or death are the first manifestation of the disease. New accurate, non-invasive and safe screening methods are required that can assess the prognosis of patients during routine examinations performed on millions of people. The aim of this review was to discuss the current literature regarding the utility of non-invasive ultrasound imaging of the coronary artery in assessing a patient's prognosis in daily practice. Assessment of coronary artery flow during common stress echocardiography or echocardiography can provide additive incremental prognostic information without the burden of radiation. Exercise or pharmacologic stress echocardiography tests combined with coronary flow velocity reserve assessment has advantages over stress tests based only on regional wall motion abnormalities. Scanning of main coronary arteries as an addition to routine echocardiography can reveal patients at high risk of adverse cardiac events in the near future.

The obesity paradox in the stress echo lab: fat is better for hearts with ischemia or coronary microvascular dysfunction

BACKGROUND

Obesity is an independent risk factor for coronary artery disease (CAD), but once CAD has developed it has been associated with improved survival ("obesity paradox").

AIM

To assess how obesity affects prognosis in patients with or without inducible ischemic regional wall motion abnormalities (RWMA) and/or abnormal coronary flow velocity reserve (CFVR) during stress echocardiography (SE).

METHODS

In an observational retrospective two- center study design, we analyzed 3249 consecutive patients (1907 men; age 66 ± 12 years; body mass index, BMI, 26.9 ± 4.1 kg/m²) with known (n = 1306) or suspected (n = 1943) CAD who underwent dipyridamole SE with simultaneous evaluation of RWMA and CFVR. All-cause death was the outcome end-point.

RESULTS

1075 patients were lean (BMI 18.5-24.9 kg/m²), 1523 overweight (BMI 25.0-29.9 kg/m²), and 651 obese (≥30.0 kg/m²). Ischemic test result for RWMA occurred in 28 (3%) lean, 69 (4%) overweight, and 28 (4%) obese patients (p = 0.03). An abnormal CFVR (≤2.0) was found in 281 (26%) lean, 402 (26%) overweight and 170 (26%) obese patients (p = 0.99). During 68 ± 44 months of follow-up, 496 (15%) patients died. At multivariable Cox analysis, BMI ≥ 30 was an independent predictor of reduced mortality in the 878 patients with stress-induced (≥2 segments) RWMA and/or CFVR abnormality (HR 0.58, 95% CI 0.40-0.84; p = 0.003), while showed no effect at univariate analysis in the 2371 patients with no RWMA and normal CFVR (HR 1.04, 95% CI 0.74-1.46; p = 0.84).

CONCLUSIONS

Obesity exerts a "paradoxical" protective effect in patients with stress-induced ischemia and/ or coronary microvascular dysfunction, and shows a neutral effect in patients with normal CFVR and no stress-induced RWMA.

Coronary flow reserve is related to the extension and transmurality of myocardial necrosis and predicts functional recovery after acute myocardial infarction

BACKGROUND

Few studies have examined the effect of transmurality of myocardial necrosis on coronary microcirculation. The aim of this study was to examine the influence of cardiac magnetic resonance-derived (GE-MRI) structural determinants of coronary flow reserve (CFR) after anterior myocardial infarction (STEMI), and their predictive value on regional functional recovery.

METHODS

Noninvasive CFR and GE-MRI were studied in 37 anterior STEMI patients after primary coronary angioplasty. The wall motion score index in the left descending anterior coronary artery territory (A-WMSI) was calculated at admission and follow-up (FU). Recovery of regional left ventricular (LV) function was defined as the difference in A-WMSI at admission and FU. The necrosis score index (NSI) and transmurality score index (TSI) by GE-MRI were calculated in the risk area. Baseline (BMR) and hyperemic (HMR) microvascular resistance, arteriolar resistance index (ARI), and coronary resistance reserve (CRR) were calculated at the Doppler echocardiography.

RESULTS

Bivariate analysis indicated that the CPK and troponin I peak, heart rate, NSI, TSI, BMR, the ARI, and CRR were related to CFR. Multivariable analysis revealed that TSI was the only independent determinant of CFR. The CFR value of >2.27, identified as optimal by ROC analysis, was 77% specific and 73% sensitive with accuracy of 76% in identifying patients with functional recovery.

CONCLUSIONS

Preservation of microvascular function after AMI is related to the extent of transmurality of myocardial necrosis, is an important factor influencing regional LV recovery, and can be monitored by noninvasive CFR.