Coronary flow velocity reserve predicts adverse prognosis in women with angina and no obstructive coronary artery disease: results from the iPOWER study

Abstract

Aims Many patients with angina, especially women, do not have obstructive coronary artery disease (CAD) yet have impaired prognosis. We investigated whether routine assessment of coronary microvascular dysfunction (CMD) is feasible and predicts adverse outcome in women with angina and no obstructive CAD. Methods and results After screening 7253, we included 1853 women with angina and no obstructive CAD on angiogram who were free of previous CAD, heart failure, or valvular heart disease in the prospective iPOWER (Improving Diagnosis and Treatment of Women with Angina Pectoris and Microvascular Disease) study. CMD was assessed by Doppler echocardiography in the left anterior descending artery as coronary flow velocity reserve (CFVR). Patients were followed for a composite outcome of cardiovascular death, myocardial infarction (MI), heart failure, stroke, and coronary revascularization. CFVR was obtained in 1681 patients (91%) and the median CFVR was 2.33 (quartiles 1–3: 2.00–2.74). During a median follow-up of 4.5 years, 96 events occurred. In univariate Cox regression, CFVR was associated with the composite outcome {hazard ratio (HR) 1.07 [95% confidence interval (CI) 1.03–1.11] per 0.1 unit decrease in CFVR; P < 0.001}, primarily driven by an increased risk of MI and heart failure. Results remained significant in multivariate analysis [HR 1.05 (95% CI 1.01–1.09) per 0.1 unit decrease in CFVR; P = 0.01]. In exploratory analyses, CFVR was also associated with the risk of repeated hospital admission for angina and all-cause mortality. Conclusion Assessment of CFVR by echocardiography is feasible and predictive of adverse outcome in women with angina and no obstructive CAD. Results support a more aggressive preventive management of these patients and underline the need for trials targeting CMD.

Coronary Flow, Left Ventricular Contractile and Heart Rate Reserve in Non-Ischemic Heart Failure

“…The analysis of composite end-points confirmed the incremental value of each of the three components of the DSE score. As significant endpoints of outcome, we considered not only mortality and HF hospitalization, but also non-fatal myocardial infarction and non-fatal stroke, In fact, HF is a risk factor for stroke even in patients with normal sinus rhythm [ 22 ], and myocardial infarction can occur in the follow-up of patients initially considered non-ischemic for a pathogenetic role of coronary microvascular disease in inducing a vulnerability to subsequent myocardial infarction in the presence of angio-graphically insignificant atherosclerosis [ 23 ].…”

Coronary Microvascular Angina: A State-of-the-Art Review

“…Transthoracic Doppler echocardiography evaluates the flow in the middle left anterior descending by color-Doppler and the CBF velocity is assessed by pulsed Doppler wave. This technique is largely available but it is operator-dependent and some patients do not have good echocardiographic window ( 31 , 32 ).…”

“…In the iPOWER study by Schroder et al, CMD was assessed by Doppler echocardiography in the left anterior descending artery as coronary flow velocity reserve. A median value of 2.33 was associated with a higher risk of MI and heart failure at a median follow-up of 4.5 years ( 32 ).…”

Microvascular Angina: Diagnosis and Management

“…A recent report from the iPOWER study showed that echocardiography-derived coronary flow velocity reserve (CFVR) of 2.33 predicted MACE including non-fatal MI and heart failure (HR 1.07; 95% CI [1.03–1.11] per 0.1 unit decrease; p<0.001) over a median of 4.5 years follow-up. [ 32 ] Zhou et al showed that stress perfusion cardiac magnetic resonance (CMR)-derived myocardial perfusion reserve index (MPRI) <1.47 predicted MACE including all-cause death, acute coronary syndrome, epicardial CAD development, heart failure hospitalisation and non-fatal stroke (HR 3.14; 95% CI [1.58–6.25]; p=0.001) over a median of 5.5 years follow-up. [ 33 ] Additionally, Murthy et al showed that cardiac-PET-derived CFR <2.0 predicted MACE including cardiac death, MI, late revascularisation or heart failure hospitalisation at 3 years compared to patients with higher CFR.…”

“…Recently, CFVR has demonstrated a prognostic value, with data from the iPOWER study showing that CFVR <2.3 predicted MACE and heart failure hospitalisation. [ 32 ] Furthermore, Gan et al showed that TDE-CFR value of ≤2.0 was an independent predictor of MACE (HR 4.63; 95% CI [2.78–7.69]; p<0.001) over a median of 4.5 years follow-up. [ 45 ]…”