Screening Patients for Elevated Left Ventricular End‐Diastolic Pressure Using a Novel Noninvasive Brachial Cuff–ECG System: A Multicenter Validation Study

BACKGROUND: Measurement of left ventricular end-diastolic pressure (LVEDP) is an established diagnostic method to evaluate heart failure but requires an invasive procedure. A noninvasive technique for detecting elevated LVEDP would improve the diagnosis of heart failure. Herein, we present the results of a multicenter study to validate a noninvasive system to detect elevated LVEDP. METHODS: The Vivio System includes a modified blood pressure cuff and single-lead ECG to capture brachial artery waveforms. A model was created to identify patients with elevated LVEDP (>18 mm Hg). For the invasive cohort, all patients were referred for coronary angiography and left heart catheterization for clinical indications. A group of 321 patients with no significant health problems were enrolled as a control cohort. Invasive LVEDP measurements were performed using Millar catheters. The training data set (n=262) contained 101 patients with LVEDP measurements (n=44 with LVEDP >18 mm Hg) and 161 controls. The validation data set (n=155) contained 75 patients with LVEDP measurements (n=40 with LVEDP >18 mm Hg) and 80 controls. RESULTS: Leave-one-out cross-validation on the training data set yielded a sensitivity of 0.84 (95% CI, 0.70-0.93]) and a specificity of 0.84 (95% CI, 0.79-0.89). The validation data set showed a sensitivity of 0.80 (95% CI, 0.64-0.91) and a specificity of 0.83 (95% CI, 0.75-0.90). CONCLUSIONS: The Vivio System can accurately detect elevated LVEDP and has the potential to significantly improve early detection of heart failure in the outpatient setting.