Mid-range Ejection Fraction Does Not Permit Risk Stratification Among Patients Hospitalized for Heart Failure

Prevalence, Characteristics, Management and Outcomes of Patients with Heart Failure with Preserved, Mildly Reduced, and Reduced Ejection Fraction in Spain

Objective: To estimate the prevalence, incidence, and describe the characteristics and management of patients with heart failure with preserved (HFpEF), mildly reduced (HFmrEF), and reduced ejection fraction (HFrEF) in Spain. Methods: Adults with ≥1 inpatient or outpatient HF diagnosis between 1 January 2013 and 30 September 2019 were identified through the BIG-PAC database. Annual incidence and prevalence by EF phenotype were estimated. Characteristics by EF phenotype were described in the 2016 and 2019 HF prevalent cohorts and outcomes in the 2016 HF prevalent cohort. Results: Overall, HF incidence and prevalence were 0.32/100 person-years and 2.34%, respectively, but increased every year. In 2019, 49.3% had HFrEF, 38.1% had HFpEF, and 4.3% had HFmrEF (in 8.3%, EF was not available). Compared with HFrEF, patients with HFpEF were largely female, older, and had more atrial fibrillation but less atherosclerotic cardiovascular disease. Among patients with HFrEF, 76.3% were taking renin-angiotensin system inhibitors, 69.5% beta-blockers, 36.8% aldosterone antagonists, 12.5% sacubitril/valsartan and 6.7% SGLT2 inhibitors. Patients with HFpEF and HFmrEF took fewer HF drugs compared to HFrEF. Overall, the event rates of HF hospitalization were 231.6/1000 person-years, which is more common in HFrEF patients. No clinically relevant differences were found in patients with HFpEF, regardless EF (50- < 60% vs. ≥60%). Conclusions: >2% of patients have HF, of which around 50% have HFrEF and 40% have HFpEF. The prevalence of HF is increasing over time. Clinical characteristics by EF phenotype are consistent with previous studies. The risk of outcomes, particularly HF hospitalization, remains high, likely related to insufficient HF treatment.

Renal Function Impact in the Prognostic Value of Galectin-3 in Acute Heart Failure

Introduction

Galectin-3 (Gal-3) is an inflammatory marker associated with the development and progression of heart failure (HF). A close relationship between Gal-3 levels and renal function has been observed, but data on their interaction in patients with acute HF (AHF) are scarce. We aim to assess the prognostic relationship between renal function and Gal-3 during an AHF episode.

Materials and Methods

This is an observational, prospective, multicenter registry of patients hospitalized for AHF. Patients were divided into two groups according to estimated glomerular filtration rate (eGFR): preserved renal function (eGFR ≥ 60 mL/min/1.73 m²) and renal dysfunction (eGFR <60 mL/min/1.73 m²). Cox regression analysis was performed to evaluate the association between Gal-3 and 12-month mortality.

Results

We included 1,201 patients in whom Gal-3 values were assessed at admission. The median value of Gal-3 in our population was 23.2 ng/mL (17.3–32.1). Gal-3 showed a negative correlation with eGFR (rho = −0.51; p < 0.001). Gal-3 concentrations were associated with higher mortality risk in the multivariate analysis after adjusting for eGFR and other prognostic variables [HR = 1.010 (95%-CI: 1.001–1.018); p = 0.038]. However, the prognostic value of Gal-3 was restricted to patients with renal dysfunction [HR = 1.010 (95%-CI: 1.001–1.019), p = 0.033] with optimal cutoff point of 31.5 ng/mL, with no prognostic value in the group with preserved renal function [HR = 0.990 (95%-CI: 0.964–1.017); p = 0.472].

Conclusions

Gal-3 is a marker of high mortality in patients with acute HF and renal dysfunction. Renal function influences the prognostic value of Gal-3 levels, which should be adjusted by eGFR for a correct interpretation.

Heart Failure With Mid-range Ejection Fraction: Every Coin Has Two Sides

This review summarizes current knowledge regarding clinical epidemiology, pathophysiology, and prognosis for patients with HFmrEF in comparison to HFrEF and HFpEF. Although recommended treatments currently focus on aggressive management of comorbidities, we summarize potentially beneficial therapies that can delay the process of heart failure by blocking the pathophysiology mechanism. More studies are needed to further characterize HFmrEF and identify effective management strategies that can reduce cardiovascular morbidity and mortality of patients with HFmrEF.

Evaluation of the prescribing practice of guideline-directed medical therapy among ambulatory chronic heart failure patients

BACKGROUND

Studies have demonstrated that heart failure (HF) patients who receive direct pharmacist input as part of multidisciplinary care have better clinical outcomes. This study evaluated/compared the difference in prescribing practices of guideline-directed medical therapy (GDMT) for chronic HF patients between two multidisciplinary clinics-with and without the direct involvement of a pharmacist.

METHODS

A retrospective audit of chronic HF patients, presenting to two multidisciplinary outpatient clinics between March 2005 and January 2017, was performed; a Multidisciplinary Ambulatory Consulting Service (MACS) with an integrated pharmacist model of care and a General Cardiology Heart Failure Service (GCHFS) clinic, without the active involvement of a pharmacist.

RESULTS

MACS clinic patients were significantly older (80 vs. 73 years, p < .001), more likely to be female (p < .001), and had significantly higher systolic (123 vs. 112 mmHg, p < .001) and diastolic (67 vs. 60 mmHg, p < .05) blood pressures compared to the GCHF clinic patients. Moreover, the MACS clinic patients showed more polypharmacy and higher prevalence of multiple comorbidities. Both clinics had similar prescribing rates of GDMT and achieved maximal tolerated doses of angiotensin-converting enzyme inhibitors (ACEIs) and angiotensin receptor blockers (ARBs) in HFrEF. However, HFpEF patients in the MACS clinic were significantly more likely to be prescribed ACEIs/ARBs (70.5% vs. 56.2%, p = 0.0314) than the GCHFS patients. Patients with both HFrEF and HFpEF (MACS clinic) were significantly less likely to be prescribed β-blockers and mineralocorticoid receptor antagonists. Use of digoxin in chronic atrial fibrillation (AF) in MACS clinic was significantly higher in HFrEF patients (82.5% vs. 58.5%, p = 0.004), but the number of people anticoagulated in presence of AF (27.1% vs. 48.0%, p = 0.002) and prescribed diuretics (84.0% vs. 94.5%, p = 0.022) were significantly lower in HFpEF patients attending the MACS clinic. Age, heart rate, systolic blood pressure (SBP), anemia, chronic renal failure, and other comorbidities were the main significant predictors of utilization of GDMT in a multivariate binary logistic regression.

CONCLUSIONS

Lower prescription rates of some medications in the pharmacist-involved multidisciplinary team were found. Careful consideration of demographic and clinical characteristics, contraindications for use of medications, polypharmacy, and underlying comorbidities is necessary to achieve best practice.

Survival of Patients with Acute Heart Failure and Mid-range Ejection Fraction in a Developing Country - A Cohort Study in South Brazil

BACKGROUND

Heart Failure with mid-range Ejection Fraction (HFmEF) was recently described by European and Brazilian guidelines on Heart Failure (HF). The ejection fraction (EF) is an important parameter to guide therapy and prognosis. Studies have shown conflicting results without representative data from developing countries.

OBJECTIVE

To analyze and compare survival rate in patients with HFmEF, HF patients with reduced EF (HFrEF), and HF patients with preserved EF (HFpEF), and to evaluate the clinical characteristics of these patients.

METHODS

A cohort study that included adult patients with acute HF admitted through the emergency department to a tertiary hospital, reference in cardiology, in south Brazil from 2009 to 2011. The sample was divided into three groups according to EF: reduced, mid-range and preserved. A Kaplan-Meier curve was analyzed according to the EF, and a logistic regression analysis was done. Statistical significance was established as p < 0.05.

RESULTS

A total of 380 patients were analyzed. Most patients had HFpEF (51%), followed by patients with HFrEF (32%) and HFmEF (17%). Patients with HFmEF showed intermediate characteristics related to age, blood pressure and ventricular diameters, and most patients were of ischemic etiology. Median follow-up time was 4.0 years. There was no statistical difference in overall survival or cardiovascular mortality (p=.0031) between the EF groups (reduced EF: 40.5% mortality; mid-range EF 39.7% and preserved EF 26%). Hospital mortality was 7.6%.

CONCLUSION

There was no difference in overall survival rate between the EF groups. Patients with HFmEF showed higher mortality from cardiovascular diseases in comparison with HFpEF patients. (Arq Bras Cardiol. 2021; 116(1):14-23).

Differential characteristics of acute heart failure in very elderly patients: the prospective RICA study

INTRODUCTION

Acute heart failure (AHF) is a frequent epidemic in geriatrics. The main aim of this study was to evaluate the clinical and prognostic differences of very elderly patients with AHF compared to the rest, and evaluate the factors associated with 90-day mortality.

METHODS

We analyzed 3828 patients hospitalized for AHF with an age of ≥ 70 years. The population was divided into three groups: 70-79, 80-89 and ≥ 90 years old (nonagenarians). The baseline characteristics of patients nonagenarians were compared with the rest. In the group of nonagenarians, their clinical characteristics were analyzed according to the left ventricular ejection fraction (LVEF) and the factors associated with mortality at 90 days of follow-up.

RESULTS

Nonagenarians showed higher comorbidity and cognitive deterioration, worse basal functional status, and preserved LVEF. Alternatively, they presented a lower rate of diabetes mellitus, lower incidence of de novo AHF, and lower prescription of angiotensin-converting-enzyme inhibitors, aldosterone blockers, anticoagulants, and statins at hospital discharge. Of the total, 334 patients (9.3%) had died by 90 days. The 90-day mortality rate was highest in nonagenarians (7.1% vs 9.8% vs 17%; p = 0.001). Multivariate analysis showed that renal failure, New York Heart Association (NYHA) functional classifications of III-IV, and a more advanced functional deterioration at baseline are predictors of mortality within 90 days.

CONCLUSIONS

The AHF in patients nonagenarians has a different clinical profile compared to younger patients and a higher mortality. In this subgroup of patients having a worse baseline functional status, higher NYHA classification (III-IV), and renal failure are predictors of 90-day mortality.

Rehospitalization burden and morbidity risk in patients with heart failure with mid-range ejection fraction

Aims

Heart failure with mid‐range ejection fraction (HFmrEF) has been proposed as a distinct HF phenotype, but whether patients on this category fare worse, similarly, or better than those with HF with reduced EF (HFrEF) or preserved EF (HFpEF) in terms of rehospitalization risks over time remains unclear.

Methods and results

We prospectively included 2961 consecutive patients admitted for acute HF (AHF) in our institution. Of them, 158 patients died during the index admission, leaving the sample size to be 2803 patients. Patients were categorized according to their EF: HFrEF if EF ≤ 40% (n = 908, 32.4%); HFmrEF if EF = 41–49% (n = 449, 16.0%); and HFpEF if EF ≥ 50% (n = 1446, 51.6%). Covariate‐adjusted incidence rate ratios (IRRs) were used to evaluate the association between EF status and recurrent all‐cause and HF‐related admissions. At a median follow‐up of 2.6 years (inter‐quartile range: 1.0–5.3), 1663 (59.3%) patients died, and 6035 all‐cause readmissions were registered in 2026 patients (72.3%), 2163 of them HF related. Rates of all‐cause readmission per 100 patients‐years of follow‐up were 150.1, 176.9, and 163.6 in HFrEF, HFmrEF, and HFpEF, respectively (P = 0.097). After multivariable adjustment, when compared with that of patients with HFrEF and HFpEF, HFmrEF status was not significantly associated with a different risk of all‐cause readmissions (IRR = 0.99; 95% confidence interval [CI], 0.77–1.27; P = 0.926; and IRR = 0.93; 95% CI, 0.74–1.18; P = 0.621, respectively) or HF‐related readmissions (IRR = 1.06; 95% CI, 0.77–1.46; P = 0.725; and IRR = 1.11; 95% CI, 0.82–1.50; P = 0.511, respectively).

Conclusions

Following an admission for AHF, patients with HFmrEF had a similar rehospitalization burden and a similar risk of recurrent all‐cause and HF‐related admissions than had patients with HFrEF or HFpEF. Regarding morbidity risk, HFmrEF seems not to be a distinct HF phenotype.

Heart Failure with Mid-Range Ejection Fraction - State of the Art

In 2016, the European Society of Cardiology (ESC) recognized heart failure (HF) with ejection fraction between 40 and 49% as a new HF phenotype, HF with mid-range ejection fraction (HFmrEF), with the main purpose of encouraging studies on this new category. In 2018, the Brazilian Society of Cardiology adhered to this classification and introduced HFmrEF in Brazil. This paper presents a narrative review of what the literature has described about HFmrEF. The prevalence of patients with HFmrEF ranged from 13 to 24% of patients with HF. Analyzing the clinical characteristics, HFmrEF shows intermediate characteristics or is either similar to HF with preserved ejection fraction (HFpEF) or to HF with reduced fraction (HFrEF). Regarding the prognosis, HFmrEF's all-cause mortality is similar to HFpEF's and lower than HFrEF's. Studies that analyzed cardiac mortality concluded that there was no significant difference between HFmrEF and HFrEF, both of which were lower than HFpEF. Despite the significant increase of publications on HFmrEF, there is a great scarcity of prospective studies and clinical trials that allow delineating specific therapies for this new phenotype. To better treat HFmrEF patients, it is fundamental that cardiologists and internists understand the differences and similarities of this new phenotype.

The prognosis of mid-range ejection fraction heart failure: a systematic review and meta-analysis

AIMS

Mid-range ejection fraction is a new entity of heart failure (HF) with undetermined prognosis till now. In our systematic review and meta-analysis, we assess the mortality and hospitalization rates in mid-range ejection fraction HF (HFmrEF) and compare them with those of reduced ejection fraction heart failure (HFrEF) and preserved ejection fraction HF (HFpEF).

METHODS AND RESULTS

We conducted our search in March 2018 in the following databases for relevant articles: PubMed, CENTRAL, Google Scholar, Web of Science, Scopus, NYAM, SIEGLE, GHL, VHL, and POPLINE. Our primary endpoint was assessing all-cause mortality and all-cause hospital re-admission rates in HFmrEF in comparison with HFrEF and HFpEF. Secondary endpoints were the possible causes of death and hospital re-admission. Twenty-five articles were included in our meta-analysis with a total of 606 762 adult cardiac patients. Our meta-analysis showed that HFmrEF had a lower rate of all-cause death than had HFrEF [relative risk (RR), 0.9; 95% confidence interval (CI), 0.85-0.94]. HFpEF showed a higher rate of cardiac mortality than did HFmrEF (RR, 1.09; 95% CI, 1.02-1.16). Also, HFrEF had a higher rate of non-cardiac mortality than had HFmrEF (RR, 1.31; 95% CI, 1.22-1.41).

CONCLUSIONS

We detected a significant difference between HFrEF and HFmrEF regarding all-cause death, and non-cardiac death, while HFpEF differed significantly from HFmrEF regarding cardiac death.

Is heart failure with mid range ejection fraction (HFmrEF) a distinct clinical entity or an overlap group?

Background

The new category of heart failure (HF), Heart Failure with mid range Ejection Fraction (HFmrEF) has recently been proposed with recent publications reporting that HFmrEF represents a transitional phase. The aim of this study was to determine the prevalence and clinical characteristics of patients with HFmrEF and to establish what proportion of patients transitioned to other types of HF, and how this affected clinical outcomes.

Methods and results

Patients were diagnosed with HF according to the 2016 ESC guidelines. Clinical outcomes and variables were recorded for all consecutive in-patients referred to the heart failure service. In total, 677 patients with new HF were identified; 25.6% with HFpEF, 21% with HFmrEF and 53.5% with HFrEF. While clinical characteristics and prognostic factors of HFmrEF were intermediate between HFrEF and HFpEF, HFmrEF patients had the best outcome, with higher mortality in the HFrEF population (p 0.02) and higher HF rehospitalisation rates in the HFpEF population (p < 0.01).38.7% of the HFmrEF patients transitioned (56.4% to HFpEF and 43.6% to HFrEF) with fewest deaths in the patients that transitioned to HFpEF (p 0.04), and fewest HF readmissions in the patients that remained as HFmrEF (<0.01).

Conclusion

HFmrEF patients had the best outcomes, compared to high rates of mortality seen in patients with HFrEF and high rates of HF readmissions seen in patients with HFpEF. Only 1/3 of HFmrEF patients transitioned during follow up, with the lowest mortality seen in patients transitioning to HFpEF.

The midrange left ventricular ejection fraction (LVEF) is associated with higher all-cause mortality during the 1-year follow-up compared to preserved LVEF among real-world patients with acute heart failure: a single-center propensity score-matched analysis

The objectives of the study were to characterize and compare different acute heart failure (AHF) subgroups according to left-ventricular ejection fraction (LVEF) in terms of all-cause mortality and HF-related readmissions during the 1-year follow-up (FU). Three hundred and fifty-six AHF patients admitted to Cardiology ward and/or CCU were retrospectively included in the study and analyzed during the 1-year FU. Patients were stratified according to LVEF as those with preserved (HFpEF), midrange (HFmrEF) and reduced LVEF (HFrEF). During the FU period, 148 (43.3%) patients died, and 116 HF-related readmission events were recorded. HFmrEF group had significantly higher standardized all-cause mortality rate, unadjusted for age, compared to HFpEF group and significantly lower than HFrEF group (41 vs. 18 and 41 vs. 62.5 events per 100 patient-years; χ² = 41.08, p < 0.001 and χ² = 16.62, p < 0.001, respectively). A propensity score-matched analysis in which all HF groups were matched for age and other covariates confirmed that HFmrEF group had significantly higher all-cause mortality rate than HFpEF group (χ² = 15.66, p < 0.001) while no significant differences in readmission rates were observed across all groups (p = NS). The hazard risk for a composite endpoint of death and readmission was highest in HFrEF group (HR 6.53, 95% CI 3.53-12.08, p < 0.001), followed by HFmrEF group (HR 3.30, 95% CI 1.86-5.87, p < 0.001) when compared to HFpEF group set as a reference. Among AHF patients, the HFmrEF phenotype was associated with significantly higher all-cause mortality compared to HFpEF, during the 1-year FU. This finding might implicate more stringent clinical approach towards this patient group.

Fate of Acute Heart Failure Patients With Mid-Range Ejection Fraction

BACKGROUND

The outcomes of heart failure (HF) with mid-range ejection fraction (HFmrEF) have been rarely studied, and follow-up data on left ventricular ejection fraction (LVEF) are scarse.Methods and Results:Patients were selected from a prospective multicenter registry of patients hospitalized for acute HF and then classified in the improved group if they exhibited %LVEF change ≥5 with follow-up LVEF ≥50%. Follow-up LVEF reported at least 90 days after discharge was used for classification. Of the 3,085 patients with acute HF, 454 were classified in the HFmrEF, and 276 had follow-up data. Of these 276 patients, 34.1% were classified in the improved group. Multivariate analysis revealed that hypertension, higher heart rate, lower serum sodium level, and maintenance therapy with β-blocker were associated with improved LVEF. The survival rate was significantly higher in the improved group than in the other groups. Young age and maintenance therapy with renin-angiotensin system blockers or aldosterone antagonists were significantly associated with better survival in HFmrEF.

CONCLUSIONS

One-third of HFmrEF patients showed improved LVEF; moreover, the survival rate in the improved group was higher than the other groups. Renin-angiotensin system blockers and aldosterone antagonists could improve the survival of HFmrEF patients.

Characteristics and long-term prognosis of patients with heart failure and mid-range ejection fraction compared with reduced and preserved ejection fraction: a systematic review and meta-analysis

Aims

This study aimed to assess by a meta‐analysis the clinical characteristics, all‐cause and cardiovascular mortality, and hospitalization of patients with heart failure (HF) with mid‐range ejection fraction (HFmrEF) compared with HF with reduced ejection fraction (HFrEF) and HF with preserved ejection fraction (HFpEF).

Methods and results

Data from 12 eligible observational studies including 109 257 patients were pooled. HFmrEF patients were significantly different and occupied a mid‐position between HFrEF and HFpEF: mean age 73.6 ± 9.8 vs. 72.6 ± 9.8 and 77.6 ± 7.2 years, male gender 59% vs. 68.5% and 40%, ischaemic heart disease 49% vs. 52.6% and 39.4%, hypertension 67.3% vs. 61.5% and 76.5%, atrial fibrillation 45.2% vs. 39.6% and 46%, chronic obstructive pulmonary disease 26.4% vs. 24.9% and 30.5%, estimated glomerular filtration rate 62 ± 30 vs. 63.3 ± 23 and 59 ± 22.5, use of renin–angiotensin system inhibitors 79.6% vs. 90.1% and 68.7%, beta‐blockers 82% vs. 89% and 73.5%, and aldosterone antagonists 20.3 vs. 31.5% and 26%, P‐values < 0.05. After a mean follow‐up of 31 ± 5 months, all‐cause mortality was significantly lower in HFmrEF than in HFrEF and HFpEF (26.8% vs. 29.5% and 31%): risk ratio (RR) 0.95 [0.93–0.98; 95% confidence interval (CI)], P < 0.001, and 0.97 (0.94–0.99; 95% CI), P = 0.014, respectively. Cardiovascular mortality was lowest in HFmrEF (9.7% vs. 13% and 12.8%): RR = 0.81 (0.73–0.91), P < 0.001, and 1.10 (0.97–1.24; 95% CI), P = 0.13, respectively. HF hospitalization in HFmrEF compared to that in HFrEF and HFpEF was 23.9% vs. 27.6% and 23.3% with RR = 0.89 (0.85–0.93), P < 0.001, and RR = 1.12 (1.07–1.17), P < 0.001, respectively.

Conclusions

The results of this study support that HFmrEF is a distinct category characterized by a mid‐position between HFrEF and HFpEF and with the lowest all‐cause and cardiovascular mortality.

Heart Failure with Mid-Range Ejection Fraction and How to Treat It

The introduction of heart failure (HF) with mid-range ejection fraction (HFmrEF) as a distinct phenotype has achieved its aim of stimulating research into the underlying characteristics, pathophysiology and treatment of HF patients with left ventricular ejection fraction of 40-49 %. Comparison of clinical characteristics, comorbidities, outcomes and prognosis among patients with HF with preserved ejection fraction, HFmrEF and HF with reduced ejection fraction allowed consideration of HFmrEF as an intermediate phenotype, which often resembles HF with reduced ejection fraction more than HF with preserved ejection fraction. The latest findings suggest that patients with HFmrEF seem to benefit from therapies that have been shown to improve outcomes in HF with reduced ejection fraction.

Clinical characteristics, one-year change in ejection fraction and long-term outcomes in patients with heart failure with mid-range ejection fraction: a multicentre prospective observational study in Catalonia (Spain)

OBJECTIVES

The aim of this study was to analyse baseline characteristics and outcome of patients with heart failure and mid-range left ventricular ejection fraction (HFmrEF, left ventricular ejection fraction (LVEF) 40%-49%) and the effect of 1-year change in LVEF in this group.

SETTING

Multicentre prospective observational study of ambulatory patients with HF followed up at four university hospitals with dedicated HF units.

PARTICIPANTS

Fourteen per cent (n=504) of the 3580 patients included had HFmrEF.

INTERVENTIONS

Baseline characteristics, 1-year LVEF and outcomes were collected. All-cause death, HF hospitalisation and the composite end-point were the primary outcomes.

RESULTS

Median follow-up was 3.66 (1.69-6.04) years. All-cause death, HF hospitalisation and the composite end-point were 47%, 35% and 59%, respectively. Outcomes were worse in HF with preserved ejection fraction (HFpEF) (LVEF>50%), without differences between HF with reduced ejection fraction (HFrEF) (LVEF<40%) and HFmrEF (all-cause mortality 52.6% vs 45.8% and 43.8%, respectively, P=0.001). After multivariable Cox regression analyses, no differences in all-cause death and the composite end-point were seen between the three groups. HF hospitalisation and cardiovascular death were not statistically different between patients with HFmrEF and HFrEF. At 1-year follow-up, 62% of patients with HFmrEF had LVEF measured: 24% had LVEF<40%, 43% maintained LVEF 40%-49% and 33% had LVEF>50%. While change in LVEF as continuous variable was not associated with better outcomes, those patients who evolved from HFmrEF to HFpEF did have a better outcome. Those who remained in the HFmrEF and HFrEF groups had higher all-cause mortality after adjustment for age, sex and baseline LVEF (HR 1.96 (95% CI 1.08 to 3.54, P=0.027) and HR 2.01 (95% CI 1.04 to 3.86, P=0.037), respectively).

CONCLUSIONS

Patients with HFmrEF have a clinical profile in-between HFpEF and HFrEF, without differences in all-cause mortality and the composite end-point between the three groups. At 1 year, patients with HFmrEF exhibited the greatest variability in LVEF and this change was associated with survival.