@article {8097, title = {Discriminative Accuracy of FEV1:FVC Thresholds for COPD-Related Hospitalization and Mortality.}, journal = {JAMA}, volume = {321}, year = {2019}, month = {2019 06 25}, pages = {2438-2447}, abstract = {

Importance: According to numerous current guidelines, the diagnosis of chronic obstructive pulmonary disease (COPD) requires a ratio of the forced expiratory volume in the first second to the forced vital capacity (FEV1:FVC) of less than 0.70, yet this fixed threshold is based on expert opinion and remains controversial.

Objective: To determine the discriminative accuracy of various FEV1:FVC fixed thresholds for predicting COPD-related hospitalization and mortality.

Design, Setting, and Participants: The National Heart, Lung, and Blood Institute (NHLBI) Pooled Cohorts Study harmonized and pooled data from 4 US general population-based cohorts (Atherosclerosis Risk in Communities Study; Cardiovascular Health Study; Health, Aging, and Body Composition Study; and Multi-Ethnic Study of Atherosclerosis). Participants aged 45 to 102 years were enrolled from 1987 to 2000 and received follow-up longitudinally through 2016.

Exposures: Presence of airflow obstruction, which was defined by a baseline FEV1:FVC less than a range of fixed thresholds (0.75 to 0.65) or less than the lower limit of normal as defined by Global Lung Initiative reference equations (LLN).

Main Outcomes and Measures: The primary outcome was a composite of COPD hospitalization and COPD-related mortality, defined by adjudication or administrative criteria. The optimal fixed FEV1:FVC threshold was defined by the best discrimination for these COPD-related events as indexed using the Harrell C statistic from unadjusted Cox proportional hazards models. Differences in C statistics were compared with respect to less than 0.70 and less than LLN thresholds using a nonparametric approach.

Results: Among 24 207 adults in the pooled cohort (mean [SD] age at enrollment, 63 [10.5] years; 12 990 [54\%] women; 16 794 [69\%] non-Hispanic white; 15 181 [63\%] ever smokers), complete follow-up was available for 11 077 (77\%) at 15 years. During a median follow-up of 15 years, 3925 participants experienced COPD-related events over 340 757 person-years of follow-up (incidence density rate, 11.5 per 1000 person-years), including 3563 COPD-related hospitalizations and 447 COPD-related deaths. With respect to discrimination of COPD-related events, the optimal fixed threshold (0.71; C statistic for optimal fixed threshold, 0.696) was not significantly different from the 0.70 threshold (difference, 0.001 [95\% CI, -0.002 to 0.004]) but was more accurate than the LLN threshold (difference, 0.034 [95\% CI, 0.028 to 0.041]). The 0.70 threshold provided optimal discrimination in the subgroup analysis of ever smokers and in adjusted models.

Conclusions and Relevance: Defining airflow obstruction as FEV1:FVC less than 0.70 provided discrimination of COPD-related hospitalization and mortality that was not significantly different or was more accurate than other fixed thresholds and the LLN. These results support the use of FEV1:FVC less than 0.70 to identify individuals at risk of clinically significant COPD.

}, keywords = {Aged, Aged, 80 and over, Cohort Studies, Female, Forced Expiratory Volume, Hospitalization, Humans, Male, Middle Aged, Prognosis, Proportional Hazards Models, Pulmonary Disease, Chronic Obstructive, Risk Assessment, Vital Capacity}, issn = {1538-3598}, doi = {10.1001/jama.2019.7233}, author = {Bhatt, Surya P and Balte, Pallavi P and Schwartz, Joseph E and Cassano, Patricia A and Couper, David and Jacobs, David R and Kalhan, Ravi and O{\textquoteright}Connor, George T and Yende, Sachin and Sanders, Jason L and Umans, Jason G and Dransfield, Mark T and Chaves, Paulo H and White, Wendy B and Oelsner, Elizabeth C} } @article {9160, title = {Lung function impairment and risk of incident heart failure: the NHLBI Pooled Cohorts Study.}, journal = {Eur Heart J}, volume = {43}, year = {2022}, month = {2022 06 14}, pages = {2196-2208}, abstract = {

AIMS: The aim is to evaluate associations of lung function impairment with risk of incident heart failure (HF).

METHODS AND RESULTS: Data were pooled across eight US population-based cohorts that enrolled participants from 1987 to 2004. Participants with self-reported baseline cardiovascular disease were excluded. Spirometry was used to define obstructive [forced expiratory volume in 1 s/forced vital capacity (FEV1/FVC) <0.70] or restrictive (FEV1/FVC >=0.70, FVC <80\%) lung physiology. The incident HF was defined as hospitalization or death caused by HF. In a sub-set, HF events were sub-classified as HF with reduced ejection fraction (HFrEF; EF <50\%) or preserved EF (HFpEF; EF >=50\%). The Fine-Gray proportional sub-distribution hazards models were adjusted for sociodemographic factors, smoking, and cardiovascular risk factors. In models of incident HF sub-types, HFrEF, HFpEF, and non-HF mortality were treated as competing risks. Among 31 677 adults, there were 3344 incident HF events over a median follow-up of 21.0 years. Of 2066 classifiable HF events, 1030 were classified as HFrEF and 1036 as HFpEF. Obstructive [adjusted hazard ratio (HR) 1.17, 95\% confidence interval (CI) 1.07-1.27] and restrictive physiology (adjusted HR 1.43, 95\% CI 1.27-1.62) were associated with incident HF. Obstructive and restrictive ventilatory defects were associated with HFpEF but not HFrEF. The magnitude of the association between restrictive physiology and HFpEF was similar to associations with hypertension, diabetes, and smoking.

CONCLUSION: Lung function impairment was associated with increased risk of incident HF, and particularly incident HFpEF, independent of and to a similar extent as major known cardiovascular risk factors.

}, keywords = {Adult, Heart Failure, Hospitalization, Humans, Lung, National Heart, Lung, and Blood Institute (U.S.), Prognosis, Risk Factors, Stroke Volume, United States}, issn = {1522-9645}, doi = {10.1093/eurheartj/ehac205}, author = {Eckhardt, Christina M and Balte, Pallavi P and Barr, Robert Graham and Bertoni, Alain G and Bhatt, Surya P and Cuttica, Michael and Cassano, Patricia A and Chaves, Paolo and Couper, David and Jacobs, David R and Kalhan, Ravi and Kronmal, Richard and Lange, Leslie and Loehr, Laura and London, Stephanie J and O{\textquoteright}Connor, George T and Rosamond, Wayne and Sanders, Jason and Schwartz, Joseph E and Shah, Amil and Shah, Sanjiv J and Smith, Lewis and White, Wendy and Yende, Sachin and Oelsner, Elizabeth C} }