PROGNOSTIC VALUE OF NONINVASIVE EXERCISE CARDIAC INDEX MEASUREMENTS IN PATIENTS WITH PULMONARY ARTERIAL HYPERTENSION

Abstract

SESSION TITLE: PAH Abstract PostersSESSION TYPE: Original Investigation PostersPRESENTED ON: 10/18/2022 01:30 pm - 02:30 pmPURPOSE: Background: Patients with pulmonary arterial hypertension (PAH) have a reduced ability to increase cardiac index (CI) in response to exercise due to impaired right ventricular reserve. Whether this impaired CI augmentation correlates with quality of life (QoL), or the risk of clinical deterioration in PAH is unknown. Impedance cardiography (ICG) can accurately and noninvasively measure CI in PAH.Research Question:In patients with PAH, does the change in CI (ΔCI) with exercise, assessed with ICG, predict clinical worsening at 1 year?METHODS: Study Design & Methods: Patients with WHO Group 1 PAH were recruited and performed a 6MWT according to ATS standards. A Noninvasive Cardiac System (NICaS, NIMedical) ICG was used to measure the cardiac index at rest and immediately post-test. The primary analysis will be the association between ΔCI and clinical worsening at 1-year. This interim analysis describes the association between ΔCI and 6MWD, QoL (using emPHasis-10 score), and REVEAL 2.0 risk score using Pearson correlation.RESULTS: 19 patients completed the 6MWT (mean±SD: age 60±12 years, disease duration 37±30 months, number of PAH-targeted therapies 1.9±0.8). Mean resting CI was 2.72±0.5 L/min/m2. Following the 6MWT, the mean increase in CI was 1.36±1.09 L/min/m2 (range -0.02-3.03 L/min/m2), due to increases in heart rate (13.2±11.4bpm, range -1 to 41bpm) and stroke volume (9.5±10.1ml, range -2-22.7ml). ΔCI was not associated with walk distance (r=0.26, p=0.14), REVEAL 2.0 risk score (r=0.12, p=0.33), or emPHasis-10 (r=0.24, p=0.16). CI at end-exercise was associated with walk distance (r=0.41, p=0.039). A greater heart rate augmentation was associated with poorer quality of life (r=0.41,p=0.039) and higher-risk REVEAL score (r=0.44,p=0.029), although this was not explained by a compensatory increase for impaired stroke volume augmentation.CONCLUSIONS: Interpretation: In PAH, the change in cardiac index with exercise was not associated with 6MWD, NT-pro-BNP, QoL, or clinical risk score. Greater tachycardia with exercise was associated with worse QoL and clinical risk score. A 1-year follow-up is planned to determine whether ΔCI has any potential role in predicting PAH progression.CLINICAL IMPLICATIONS: TBDDISCLOSURES: No relevant relationships by Lauren BathNo relevant relationships by David ChristiansenNo relevant relationships by Ashish Shah SESSION TITLE: PAH Abstract Posters SESSION TYPE: Original Investigation Posters PRESENTED ON: 10/18/2022 01:30 pm - 02:30 pm PURPOSE: Background: Patients with pulmonary arterial hypertension (PAH) have a reduced ability to increase cardiac index (CI) in response to exercise due to impaired right ventricular reserve. Whether this impaired CI augmentation correlates with quality of life (QoL), or the risk of clinical deterioration in PAH is unknown. Impedance cardiography (ICG) can accurately and noninvasively measure CI in PAH. Research Question:In patients with PAH, does the change in CI (ΔCI) with exercise, assessed with ICG, predict clinical worsening at 1 year? METHODS: Study Design & Methods: Patients with WHO Group 1 PAH were recruited and performed a 6MWT according to ATS standards. A Noninvasive Cardiac System (NICaS, NIMedical) ICG was used to measure the cardiac index at rest and immediately post-test. The primary analysis will be the association between ΔCI and clinical worsening at 1-year. This interim analysis describes the association between ΔCI and 6MWD, QoL (using emPHasis-10 score), and REVEAL 2.0 risk score using Pearson correlation. RESULTS: 19 patients completed the 6MWT (mean±SD: age 60±12 years, disease duration 37±30 months, number of PAH-targeted therapies 1.9±0.8). Mean resting CI was 2.72±0.5 L/min/m2. Following the 6MWT, the mean increase in CI was 1.36±1.09 L/min/m2 (range -0.02-3.03 L/min/m2), due to increases in heart rate (13.2±11.4bpm, range -1 to 41bpm) and stroke volume (9.5±10.1ml, range -2-22.7ml). ΔCI was not associated with walk distance (r=0.26, p=0.14), REVEAL 2.0 risk score (r=0.12, p=0.33), or emPHasis-10 (r=0.24, p=0.16). CI at end-exercise was associated with walk distance (r=0.41, p=0.039). A greater heart rate augmentation was associated with poorer quality of life (r=0.41,p=0.039) and higher-risk REVEAL score (r=0.44,p=0.029), although this was not explained by a compensatory increase for impaired stroke volume augmentation. CONCLUSIONS: Interpretation: In PAH, the change in cardiac index with exercise was not associated with 6MWD, NT-pro-BNP, QoL, or clinical risk score. Greater tachycardia with exercise was associated with worse QoL and clinical risk score. A 1-year follow-up is planned to determine whether ΔCI has any potential role in predicting PAH progression. CLINICAL IMPLICATIONS: TBD DISCLOSURES: No relevant relationships by Lauren Bath No relevant relationships by David Christiansen No relevant relationships by Ashish Shah