Using Pulsatility Responses to Breath-Hold Maneuvers to Predict Readmission Rates in Left Ventricular Assist Device Patients

Abstract

Purpose Respiratory maneuvers induce heterogenous changes to flow pulsatility in continuous flow left ventricular assist device patients. We assessed the association of these pulsatility responses with patient hemodynamics and outcomes. Methods Responses obtained from Medtronic HVAD outpatients during weekly clinics were categorised into three ordinal groups according to the percentage reduction in waveform pulsatility (peak - trough flow) upon inspiratory breath hold, IBH (%∆P): (1) Minimal Change (MC, %∆P≤50), (2) Reduced Pulsatility (RP, 50<%∆P<100), (3) Flatline (FL, %∆P=100). Waveforms were also assessed for IBH-induced suction. Same day echocardiography and right heart catheterization (RHC) were performed. To assess readmissions, patients with ≥1 flatline response (F group) were compared to those without (NF group) and patients with ≥1 suction (S group) were compared to those without (NS group). Results In total, 712 responses were obtained from 55 patients (45 male, age 56±12). The F group (n=28) experienced numerically lower all-cause readmissions (1.51 vs 2.79 events/y, hazard ratio [HR]=0.67, p=0.12), reduced heart failure readmissions (0.07 vs 0.56 events/y, HR=0.15, p<0.01) and superior readmission-free survival (HR=0.47, p=0.04, figure). Readmissions for syncope/presyncope occurred solely in the S group (n=18) (0.25 events/y, p=0.01). Echocardiography was performed in 50 patients and RHC in 31. When compared to MC, RP and FL responses were associated with lower right atrial (14.2 vs 11.4 vs 9.0mmHg, p=0.08) and pulmonary capillary wedge pressures (19.8 vs 14.3 vs 13.0mmHg, p=0.03), lower rates of >mild mitral regurgitation (48% vs 13% vs 10%, p=0.01) and >mild right ventricular impairment (62% vs 25% vs 27%, p=0.03), and increased rates of aortic valve opening (32% vs 50% vs 75%, p=0.03). Conclusion Responses to IBH predicted hemodynamics and readmissions. The impact of IBH on pulsatility can noninvasively guide patient management and optimization. Respiratory maneuvers induce heterogenous changes to flow pulsatility in continuous flow left ventricular assist device patients. We assessed the association of these pulsatility responses with patient hemodynamics and outcomes. Responses obtained from Medtronic HVAD outpatients during weekly clinics were categorised into three ordinal groups according to the percentage reduction in waveform pulsatility (peak - trough flow) upon inspiratory breath hold, IBH (%∆P): (1) Minimal Change (MC, %∆P≤50), (2) Reduced Pulsatility (RP, 50<%∆P<100), (3) Flatline (FL, %∆P=100). Waveforms were also assessed for IBH-induced suction. Same day echocardiography and right heart catheterization (RHC) were performed. To assess readmissions, patients with ≥1 flatline response (F group) were compared to those without (NF group) and patients with ≥1 suction (S group) were compared to those without (NS group). In total, 712 responses were obtained from 55 patients (45 male, age 56±12). The F group (n=28) experienced numerically lower all-cause readmissions (1.51 vs 2.79 events/y, hazard ratio [HR]=0.67, p=0.12), reduced heart failure readmissions (0.07 vs 0.56 events/y, HR=0.15, p<0.01) and superior readmission-free survival (HR=0.47, p=0.04, figure). Readmissions for syncope/presyncope occurred solely in the S group (n=18) (0.25 events/y, p=0.01). Echocardiography was performed in 50 patients and RHC in 31. When compared to MC, RP and FL responses were associated with lower right atrial (14.2 vs 11.4 vs 9.0mmHg, p=0.08) and pulmonary capillary wedge pressures (19.8 vs 14.3 vs 13.0mmHg, p=0.03), lower rates of >mild mitral regurgitation (48% vs 13% vs 10%, p=0.01) and >mild right ventricular impairment (62% vs 25% vs 27%, p=0.03), and increased rates of aortic valve opening (32% vs 50% vs 75%, p=0.03). Responses to IBH predicted hemodynamics and readmissions. The impact of IBH on pulsatility can noninvasively guide patient management and optimization.