Mitral E-wave to stroke volume ratio displays stronger diagnostic performance to identify elevated left ventricular filling pressures than mitral E/e' during passive leg lift: A cross-sectional study employing simultaneous echocardiography and catheterization.

BACKGROUND: Elevated filling pressure is a hallmark of heart failure (HF) and portends poor prognosis. Accurate diagnosis is challenging, given that patients with normal filling pressure at rest develop disproportionate elevation with sudden preload increase. We aimed to test the accuracy of the ratio between mitral inflow velocity (E) and left ventricular stroke volume (SV) to identify patients with elevated filling pressure with passive leg lifting (PLL) and compare this with other echocardiographic surrogates of filling pressure.

METHODS: Doppler echocardiography and right heart catheterization (RHC) were simultaneously performed in 37 patients (11 males, mean age 67 ± 12 years) with exertional dyspnea. Twenty-six healthy controls (14 males, mean age 60 ± 12 years) were added as reference. SV, cardiac output (CO), tricuspid regurgitation peak gradient (TRG), mitral E-wave (E) and early myocardial velocity (e') were obtained at rest and with PLL. E/SV, E/CO and E/e' were calculated and correlated with invasive pulmonary capillary wedge pressures (PCWP) with PLL.

RESULTS: During PLL, E/SV (AUC = 0.94) displayed stronger diagnostic ability to identify PCWP >15 mmHg than E/e' (AUC = 0.81), mitral E/A ratio (0.76) and resting invasive PCWP (0.84). An E/SV cutoff of >1.0 showed 88% sensitivity and 75% specificity to identify elevated PCWP. Further, 10 patients (27%) were reassigned during PLL from normal to postcapillary pulmonary hypertension (postCPH), and 6 patients (16%) switched diagnosis from precapillary PH (preCPH) to postCPH.

CONCLUSION: The novel E/SV ratio identifies patients with elevated PCWP with PLL and displays stronger diagnostic performance than routinely utilized echocardiographic measures such as E/e' in addition to resting, catheterization derived PCWP.