Prognostic value of alveolar volume in systolic heart failure: a prospective observational study

Association between DLCO index and the severity of heart failure: a cross-sectional study

BACKGROUND

The prognostic role of diffusing capacity of the lung for carbon monoxide (DLCO) in heart failure has not been thoroughly investigated. Therefore, this study aimed to evaluate DLCO variation in different systolic and diastolic heart failure stages.

METHODS

This was a prospective cross-sectional study on 51 patients with systolic (reduced LVEF) or diastolic (preserved LVEF) chronic heart failure (CHF). All patients underwent a standard DLCO test. The associations between the severity of heart failure and reduced carbon monoxide transfer factor (TLCO), carbon monoxide transfer coefficient (KCO), and alveolar volume (VA) were investigated. Data were analysed using SPSS software version 16. p-Values below 0.05 were considered statistically significant.

RESULTS

The mean age of participants was 59.29 ± 14.91 years, with 72% of the study population being male. Systolic heart failure was observed in 47% of patients, diastolic heart failure in 18%, and a mixed systolic and diastolic pattern in 35%. There were significant differences between TLCO percentage in patients with CHF types and the New York Heart Association (NYHA) functional classes (p = 0.042). Overall, an ejection fraction (EF) of less than 25% correlated with 3%, 53%, and 0.78 declines in TLCO, KCO%, and KCO index, respectively.

CONCLUSION

Despite the lack of statistically significant differences between DLCO indices and CHF severity, decreased DLCO parameters correlated with reduced EF. Therefore, DLCO testing might be helpful to predict HF severity.

Prognostic Role of Pulmonary Function in Patients With Heart Failure With Reduced Ejection Fraction

Background

Both ventilatory abnormalities and pulmonary hypertension (PH) are frequently observed in patients with heart failure with reduced ejection fraction. We aim to investigate the association between ventilatory abnormalities and PH in heart failure with reduced ejection fraction, as well as their prognostic impacts.

Methods and Results

A total of 440 ambulatory patients (age, 66.2±15.8 years; 77% men) with left ventricular ejection fraction ≤40% who underwent comprehensive echocardiography and spirometry were enrolled. Total lung capacity, forced vital capacity, and forced expiratory volume in the first second were obtained. Pulmonary arterial systolic pressure was estimated. PH was defined as a pulmonary arterial systolic pressure of >50 mm Hg. The primary end point was all‐cause mortality at 5 years. Patients with PH had significantly reduced total lung capacity, forced vital capacity, and forced expiratory volume in the first second. During a median follow‐up of 25.9 months, there were 111 deaths. After accounting for age, sex, body mass index, renal function, smoking, left ventricular ejection fraction, and functional capacity, total lung capacity (hazard ratio [HR] per 1 SD, 0.66; 95% CI per 1 SD, 0.46–0.96), forced vital capacity (HR per 1 SD, 0.64; 95% CI per 1 SD, 0.48–0.84), and forced expiratory volume in the first second (HR per 1 SD, 0.72; 95% CI per 1 SD, 0.53–0.98) were all significantly correlated with mortality in patients without PH. Kaplan‐Meier curve demonstrated impaired pulmonary function, defined as forced expiratory volume in the first second ≤58% of predicted or forced vital capacity ≤65% of predicted, was associated with higher mortality in patients without PH (HR, 2.85; 95% CI, 1.66–4.89), but not in patients with PH (HR, 1.05; 95% CI, 0.61–1.82).

Conclusions

Ventilatory abnormality was more prevalent in patients with heart failure with reduced ejection fraction with PH than those without. However, such ventilatory defects were related to long‐term survival only in patients without PH, regardless of their functional status.

Cardiac biomarkers retain prognostic significance in patients with heart failure and chronic obstructive pulmonary disease

AIMS

Chronic obstructive pulmonary disease (COPD) is a frequent comorbidity in patients with heart failure (HF). We assessed the influence of COPD on circulating levels and prognostic value of three HF biomarkers: N-terminal pro-B-type natriuretic peptide (NT-proBNP), high-sensitivity troponin T (hs-TnT), and soluble suppression of tumorigenesis-2 (sST2).

METHODS

Individual data from patients with chronic HF, known COPD status, NT-proBNP and hs-TnT values (n = 8088) were analysed. A subgroup (n = 3414) had also sST2 values.

RESULTS

Patients had a median age of 66 years (interquartile interval 57-74), 77% were men and 82% had HF with reduced ejection fraction. NT-proBNP, hs-TnT and sST2 were 1207 ng/l (487-2725), 17 ng/l (9-31) and 30 ng/ml (22-44), respectively. Patients with COPD (n = 1249, 15%) had higher NT-proBNP (P = 0.042) and hs-TnT (P < 0.001), but not sST2 (P = 0.165). Over a median 2.0-year follow-up (1.5-2.5), 1717 patients (21%) died, and 1298 (16%) died from cardiovascular causes; 2255 patients (28%) were hospitalized for HF over 1.8 years (0.9-2.1). NT-proBNP, hs-TnT and sST2 predicted the three end points regardless of COPD status. The best cut-offs from receiver-operating characteristics analysis were higher in patients with COPD than in those without. Patients with all three biomarkers higher than or equal to end-point- and COPD-status-specific cut-offs were also those with the worst prognosis.

CONCLUSIONS

Among patients with HF, those with COPD have higher NT-proBNP and hs-TnT, but not sST2. All these biomarkers yield prognostic significance regardless of the COPD status.

Lung diffusion capacity in advanced heart failure: relation to central haemodynamics and outcome

Aims

Patients with heart failure (HF) are known to have a reduced pulmonary diffusion capacity for carbon monoxide (D_LCO), but little is known about how lung function relates to central haemodynamics. The aim of this study was to investigate the association between haemodynamic variables and pulmonary diffusion capacity adjusted for alveolar volume in congestive HF patients and to analyse how predicted D_LCO/V_A affects mortality in relation to the haemodynamic status.

Methods and results

We retrospectively studied right heart catheterization (RHC) and lung function data on 262 HF patients (mean age 51 ± 13 years) with a left ventricular ejection fraction < 45% referred non‐urgently for evaluation for heart transplantation (HTX) or left ventricular assist device (LVAD). Univariate and multivariate linear regression models were constructed to examine the associations between predicted values of D_LCO/V_A, forced vital capacity (FVC) and forced expiratory volume in 1 s (FEV₁), and haemodynamic parameters [pulmonary capillary wedge pressure (PCWP), central venous pressure, cardiac index, mean pulmonary artery pressure, and mean arterial pressure] as well as other factors known to affect lung function in HF. FEV₁ was reduced to <80% of predicted value in 55% of the population, and D_LCO/V_A was reduced in 63% of the population. D_LCO/V_A correlated positively with pulmonary capillary wedge pressure in both univariate and multivariate analyses for all included patients (P < 0.001 and P = 0.045, respectively) and a restricted population of patients with the shortest time between RHC and lung function testing (P = 0.005, P = 0.015). D_LCO/V_A predicted mortality in multivariate models [hazard ratio 1.5 (1.1–2.1)] but not the combined endpoint of death, LVAD implantation, or HTX. There was no significant correlation between haemodynamics and predicted FVC or FEV₁.

Conclusions

Pulmonary diffusion capacity correlates positively with left ventricular fillings pressures, and reduced values predict increased mortality in patients with HF. This might be driven by increased lung capillary volume in patients with pulmonary congestion.

The effect of emphysema on readmission and survival among smokers with heart failure

Heart Failure (HF) and chronic obstructive pulmonary disease (COPD) are morbid diseases that often coexist. In patients with coexisting disease, COPD is an independent risk factor for readmission and mortality. However, spirometry is often inaccurate in those with active heart failure. Therefore, we investigated the association between the presence of emphysema on computed tomography (CT) and readmission rates in smokers admitted with heart failure (HF). The cohort included a consecutive group of smokers discharged with HF from a tertiary center between January 1, 2014 and April 1, 2014 who also had a CT of the chest for dyspnea. The primary endpoint was any readmission for HF before April 1, 2016; secondary endpoints were 30-day readmission for HF, length of stay and all-cause mortality. Over the study period, there were 225 inpatient smokers with HF who had a concurrent chest CT (155 [69%] males, age 69±11 years, ejection fraction [EF] 46±18%, 107 [48%] LVEF of < 50%). Emphysema on CT was present in 103 (46%) and these were older, had a lower BMI, more pack-years, less diabetes and an increased afterload. During a follow-up of 2.1 years, there were 110 (49%) HF readmissions and 55 (24%) deaths. When separated by emphysema on CT, any readmission, 30-day readmission, length of stay and mortality were higher among HF patients with emphysema. In multivariable regression, emphysema by CT was associated with a two-fold higher (adjusted HR 2.11, 95% CI 1.41–3.15, p < 0.001) risk of readmission and a trend toward increased mortality (adjusted HR 1.70 95% CI 0.86–3.34, p = 0.12). In conclusion, emphysema by CT is a frequent finding in smokers hospitalized with HF and is associated with adverse outcomes in HF. This under recognized group of patients with both emphysema and heart failure may benefit from improved recognition and characterization of their co-morbid disease processes and optimization of therapies for their lung disease.

Reversible decline in pulmonary function during left ventricular assist device therapy

Cardiac replacement therapy, consisting of left ventricular assist device (LVAD) implant surgery and heart transplantation, has considerably reduced the mortality and morbidity of patients with stage D heart failure. However, its impact on pulmonary function remains unclear. We retrospectively evaluated 22 consecutive patients (16 men; 42 ± 13 years old) who had undergone pulmonary function tests during the heart failure, LVAD, and heart transplantation periods. The LVAD therapy lasted an average of 871 ± 267 days. The % vital capacity and forced expiratory volume in 1 s decreased significantly after LVAD implantation and returned to baseline levels after heart transplantation. Correlation analysis indicated that a shorter duration of LVAD support was associated with a more significant improvement in % vital capacity in heart transplantation recipients, compared to the pre-LVAD period and the LVAD period. In conclusion, we provide evidence that a decrease in pulmonary function occurs during LVAD support but it may be reversible. Limited LVAD duration may be a key for the recovery of pulmonary dysfunction.

Using Laplace Regression to Model and Predict Percentiles of Age at Death When Age Is the Primary Time Scale

Increasingly often in epidemiologic research, associations between survival time and predictors of interest are measured by differences between distribution functions rather than hazard functions. For example, differences in percentiles of survival time, expressed in absolute time units (e.g., weeks), may complement the popular risk ratios, which are unitless measures. When analyzing time to an event of interest (e.g., death) in prospective cohort studies, the time scale can be set to start at birth or at study entry. The advantages of one time origin over the other have been thoroughly explored for the estimation of risks but not for the estimation of survival percentiles. In this paper, we analyze the use of different time scales in the estimation of survival percentiles with Laplace regression. Using this regression method, investigators can estimate percentiles of survival time over levels of an exposure of interest while adjusting for potential confounders. Our findings may help to improve modeling strategies and ease interpretation in the estimation of survival percentiles in prospective cohort studies.

Survival in COPD: impact of lung dysfunction and comorbidities

Chronic obstructive pulmonary disease (COPD) is a major cause of morbidity and mortality in industrialized countries. Recent studies investigated the impact of comorbidities on the survival in COPD, but most of them lacked a referent group of comorbidity-matched, nonobstructed individuals.We examined the 10-year mortality in a sample of 200 COPD patients and 201 nonobstructed controls. They were part of a larger cohort enrolled in a European case-control study aimed at assessing genetic susceptibility to COPD. By design, the COPD group included patients with a forced expiratory volume in 1 second (FEV1) ≤70% predicted. Cases and controls were matched on age, sex, and cumulative smoking history, and shared a nearly identical prevalence of cardiovascular and metabolic disorders. We estimated the hazard of death with Cox regression and percentiles of survival with Laplace regression. COPD was the main exposure variable of interest. Five comorbidities (hypertension, coronary artery disease, prior myocardial infarction, chronic heart failure, and diabetes) were included as covariates in multiple regression models.The all-cause mortality rate was significantly higher in cases than in controls (43% vs 16%, P < 0.001). The unadjusted hazard of death for COPD was 3-fold higher than the referent category (P < 0.001), and remained nearly unchanged after introducing the 5 comorbidities in multiple regression. Patients with COPD had significantly shorter survival percentiles than comorbidity-matched controls (P < 0.001). Notably, 15% of the nonobstructed controls died by 10.3 years into the study; the same proportion of COPD patients had died some 6 years earlier, at 4.6 years.In a separate analysis, we split the whole sample into 2 groups based on the lower tertile of FEV1 and carbon monoxide lung diffusing capacity (DLCO). The hazard of death for COPD patients with low FEV1 and DLCO was nearly 3.5-fold higher than in all the others (P < 0.001), and decreased only slightly after introducing age and chronic heart failure as relevant covariates.COPD is a strong predictor of reduced survival independently of coexisting cardiovascular and metabolic disorders. Efforts should be made to identify patients at risk and to ensure adherence to prescribed therapeutic regimens.