Hemodynamic profiles by non-invasive monitoring of cardiac index and vascular tone in acute heart failure patients in the emergency department: External validation and clinical outcomes

Abstract

Background Non-invasive finger-cuff monitors measuring cardiac index and vascular tone (SVRI) classify emergency department (ED) patients with acute heart failure (AHF) into three otherwise-indistinguishable subgroups. Our goals were to validate these “hemodynamic profiles” in an external cohort and assess their association with clinical outcomes. Methods AHF patients (n = 257) from five EDs were prospectively enrolled in the validation cohort (VC). Cardiac index and SVRI were measured with a ClearSight finger-cuff monitor (formerly NexFin, Edwards Lifesciences) as in a previous study (derivation cohort, DC, n = 127). A control cohort (CC, n = 127) of ED patients with sepsis was drawn from the same study as the DC. K-means cluster analysis previously derived two-dimensional (cardiac index and SVRI) hemodynamic profiles in the DC and CC (k = 3 profiles each). The VC was subgrouped de novo into three analogous profiles by unsupervised K-means consensus clustering. PERMANOVA tested whether VC profiles 1–3 differed from profiles 1–3 in the DC and CC, by multivariate group composition of cardiac index and vascular tone. Profiles in the VC were compared by a primary outcome of 90-day mortality and a 30-day ranked composite secondary outcome (death, mechanical cardiac support, intubation, new/emergent dialysis, coronary intervention/surgery) as time-to-event (survival analysis) and binary events (odds ratio, OR). Descriptive statistics were used to compare profiles by two validated risk scores for the primary outcome, and one validated score for the secondary outcome. Results The VC had median age 60 years (interquartile range {49–67}), and was 45% (n = 116) female. Multivariate profile composition by cardiac index and vascular tone differed significantly between VC profiles 1–3 and CC profiles 1–3 (p = 0.001, R2 = 0.159). A difference was not detected between profiles in the VC vs. the DC (p = 0.59, R2 = 0.016). VC profile 3 had worse 90-day survival than profiles 1 or 2 (HR = 4.8, 95%CI 1.4–17.1). The ranked secondary outcome was more likely in profile 1 (OR = 10.0, 1.2–81.2) and profile 3 (12.8, 1.7–97.9) compared to profile 2. Diabetes prevalence and blood urea nitrogen were lower in the high-risk profile 3 (p<0.05). No significant differences between profiles were observed for other clinical variables or the 3 clinical risk scores. Conclusions Hemodynamic profiles in ED patients with AHF, by non-invasive finger-cuff monitoring of cardiac index and vascular tone, were replicated de novo in an external cohort. Profiles showed significantly different risks of clinically-important adverse patient outcomes.

Point‐of‐care echocardiography of the right heart improves acute heart failure risk stratification for low‐risk patients: The REED‐AHF prospective study

“…Nevertheless, among the six or more described CDIs for ED risk stratification of AHF, none incorporate echocardiographic variables 64 . This is despite copious literature describing the utility of right heart echocardiography measures for heart failure risk prediction outside of the ED setting 6,18–37,39–46 …”

“…To increase precision in estimating the benchmark standard‐of‐care miss rate, we averaged the rate of events in discharged patients in REED‐AHF 38 with the rate observed in CLEAR‐AHF, a recent 257 prospective patient cohort from the same institution 6 . CLEAR‐AHF 6 had similar adjudication of AHF diagnosis, adjudicated outcomes for the STRATIFY risk score, and similar inclusion criteria as REED‐AHF, but was larger than REED‐AHF and had slightly lower outcome rates 38 . Among 341 patients in both cohorts, 8.3% of discharged patients experienced the primary outcome compared to 13.6% among admitted or observation patients 6,38 .…”

“…CLEAR‐AHF 6 had similar adjudication of AHF diagnosis, adjudicated outcomes for the STRATIFY risk score, and similar inclusion criteria as REED‐AHF, but was larger than REED‐AHF and had slightly lower outcome rates 38 . Among 341 patients in both cohorts, 8.3% of discharged patients experienced the primary outcome compared to 13.6% among admitted or observation patients 6,38 . Thus, 8% was chosen as the higher risk threshold to be evaluated (i.e., the least conservative integer risk threshold to still be more conservative than usual care).…”

“…While all three have validation test characteristics that exceed published performance of emergency physician (EP)‐estimated risk 9 and actual disposition decisions, 12 none were deemed sufficient to direct AHF disposition on their own. Recent multicenter studies have shown that ED discharged AHF patients experience 30‐day rates of death (3.8%) 14 and serious adverse events (7.1%) in STRATIFY's composite outcome 6 much greater than risk thresholds that EPs report as acceptable 15 . Nonetheless, in one study comparing EHMRG 9 to EP‐estimated risk, not only did EHRMG perform significantly better but EPs frequently misclassified the highest risk patients as low risk (and vice versa).…”

“…Acute heart failure (AHF) accounts for 1 million emergency department (ED) visits annually 1 and presents significant dilemmas for risk stratification and ED disposition 2 . Over 80% of AHF patients treated in United States EDs are admitted to the hospital, but as many as half may be low enough risk to avoid admission 3–6 . The forthcoming 2022 update to the American College of Emergency Physicians (ACEP) clinical policy on AHF 7 identified three validated clinical decision instruments (CDI) 8–10 that are useful for risk‐stratification: the STRATIFY risk score, 8,11 the Emergency Heart Failure Mortality Risk Grade (EHMRG), 9,12 and the Ottawa Heart Failure Risk Scale (OHFRS) 10,13 .…”