Identifying high risk clinical phenogroups of pulmonary hypertension through a clustering analysis

INTRODUCTION

The classification and management of pulmonary hypertension (PH) is challenging due to clinical heterogeneity of patients. We sought to identify distinct multimorbid phenogroups of patients with PH that are at particularly high-risk for adverse events.

METHODS

A hospital-based cohort of patients referred for right heart catheterization between 2005-2016 with PH were included. Key exclusion criteria were shock, cardiac arrest, cardiac transplant, or valvular surgery. K-prototypes was used to cluster patients into phenogroups based on 12 clinical covariates.

RESULTS

Among 5208 patients with mean age 64±12 years, 39% women, we identified 5 distinct multimorbid PH phenogroups with similar hemodynamic measures yet differing clinical outcomes: (1) "young men with obesity", (2) "women with hypertension", (3) "men with overweight", (4) "men with cardiometabolic and cardiovascular disease", and (5) "men with structural heart disease and atrial fibrillation." Over a median follow-up of 6.3 years, we observed 2182 deaths and 2002 major cardiovascular events (MACE). In age- and sex-adjusted analyses, phenogroups 4 and 5 had higher risk of MACE (HR 1.68, 95% CI 1.41-2.00 and HR 1.52, 95% CI 1.24-1.87, respectively, compared to the lowest risk phenogroup 1). Phenogroup 4 had the highest risk of mortality (HR 1.26, 95% CI 1.04-1.52, relative to phenogroup 1).

CONCLUSIONS

Cluster-based analyses identify patients with PH and specific comorbid cardiometabolic and cardiovascular disease burden that are at highest risk for adverse clinical outcomes. Interestingly, cardiopulmonary hemodynamics were similar across phenogroups, highlighting the importance of multimorbidity on clinical trajectory. Further studies are needed to better understand comorbid heterogeneity among patients with PH.

Multiple Prior Live Births Are Associated With Cardiac Remodeling and Heart Failure Risk in Women

OBJECTIVE

Greater parity has been associated with cardiovascular disease risk. We sought to find whether the effects on cardiac remodeling and heart failure risk are clear.

METHODS

We examined the association of number of live births with echocardiographic measures of cardiac structure and function in participants of the Framingham Heart Study (FHS) using multivariable linear regression. We next examined the association of parity with incident heart failure with preserved (HFpEF) or reduced (HFrEF) ejection fraction using a Fine-Gray subdistribution hazards model in a pooled analysis of n = 12,635 participants in the FHS, the Cardiovascular Health Study, the Multi-Ethnic Study of Atherosclerosis, and Prevention of Renal and Vascular Endstage Disease. Secondary analyses included major cardiovascular disease, myocardia infarction and stroke.

RESULTS

Among n = 3931 FHS participants (mean age 48 ± 13 years), higher numbers of live births were associated with worse left ventricular fractional shortening (multivariable β -1.11 (0.31); P = 0.0005 in ≥ 5 live births vs nulliparous women) and worse cardiac mechanics, including global circumferential strain and longitudinal and radial dyssynchrony (P < 0.01 for all comparing ≥ 5 live births vs nulliparity). When examining HF subtypes, women with ≥ 5 live births were at higher risk of developing future HFrEF compared with nulliparous women (HR 1.93, 95% CI 1.19-3.12; P = 0.008); by contrast, a lower risk of HFpEF was observed (HR 0.58, 95% CI 0.37-0.91; P = 0.02).

CONCLUSIONS

Greater numbers of live births are associated with worse cardiac structure and function. There was no association with overall HF, but a higher number of live births was associated with greater risk for incident HFrEF.

Association of Initial and Longitudinal Changes in C-reactive Protein With the Risk of Cardiovascular Disease, Cancer, and Mortality

OBJECTIVE

To evaluate the value of serial C-reactive protein (CRP) measurements in predicting the risk of cardiovascular disease (CVD), cancer, and mortality.

METHODS

The analysis was performed using data from two prospective, population-based observational cohorts: the Prevention of Renal and Vascular End-Stage Disease (PREVEND) study and the Framingham Heart Study (FHS). A total of 9253 participants had CRP measurements available at two examinations (PREVEND: 1997-1998 and 2001-2002; FHS Offspring cohort: 1995-1998 and 1998-2001). All CRP measurements were natural log-transformed before analyses. Cardiovascular disease included fatal and nonfatal cardiovascular, cerebrovascular and peripheral vascular events, and heart failure. Cancer included all malignancies except nonmelanoma skin cancers.

RESULTS

The mean age of the study population at baseline was 52.4±12.1 years and 51.2% (n=4733) were women. Advanced age, female sex, smoking, body mass index, and total cholesterol were associated with greater increases in CRP levels over time (Pall<.001 in the multivariable model). Baseline CRP, as well as increase in CRP over time (ΔCRP), were associated with incident CVD (hazard ratio [HR]: 1.29 per 1-SD increase; 95% confidence interval [CI]: 1.29 to 1.47, and HR per 1-SD increase: 1.19; 95% CI: 1.09 to 1.29 respectively). Similar findings were observed for incident cancer (baseline CRP, HR: 1.17; 95% CI: 1.09 to 1.26; ΔCRP, HR: 1.08; 95% CI: 1.01 to 1.15) and mortality (baseline CRP, HR: 1.29; 95% CI: 1.21 to 1.37; ΔCRP, HR: 1.10; 95% CI: 1.05 to 1.16).

CONCLUSION

Initial as well as subsequent increases in CRP levels predict future CVD, cancer, and mortality in the general population.

Association of Cardiometabolic Disease With Cancer in the Community

Background

Obesity and cardiometabolic dysfunction have been associated with cancer risk and severity. Underlying mechanisms remain unclear.

Objectives

The aim of this study was to examine associations of obesity and related cardiometabolic traits with incident cancer.

Methods

FHS (Framingham Heart Study) and PREVEND (Prevention of Renal and Vascular End-Stage Disease) study participants without prevalent cancer were studied, examining associations of obesity, body mass index (BMI), waist circumference, visceral adipose tissue (VAT) and subcutaneous adipose tissue depots, and C-reactive protein (CRP) with future cancer in Cox models.

Results

Among 20,667 participants (mean age 50 years, 53% women), 2,619 cancer events were observed over a median follow-up duration of 15 years. Obesity was associated with increased risk for future gastrointestinal (HR: 1.30; 95% CI: 1.05-1.60), gynecologic (HR: 1.62; 95% CI: 1.08-2.45), and breast (HR: 1.32; 95% CI: 1.05-1.66) cancer and lower risk for lung cancer (HR: 0.62; 95% CI: 0.44-0.87). Similarly, waist circumference was associated with increased risk for overall, gastrointestinal, and gynecologic but not lung cancer. VAT but not subcutaneous adipose tissue was associated with risk for overall cancer (HR: 1.22; 95% CI: 1.05-1.43), lung cancer (HR: 1.92; 95% CI: 1.01-3.66), and melanoma (HR: 1.56; 95% CI: 1.02-2.38) independent of BMI. Last, higher CRP levels were associated with higher risk for overall, colorectal, and lung cancer (P < 0.05 for all).

Conclusions

Obesity and abdominal adiposity are associated with future risk for specific cancers (eg, gastrointestinal, gynecologic). Although obesity was associated with lower risk for lung cancer, greater VAT and CRP were associated with higher lung cancer risk after adjusting for BMI.

Association of Pulmonary Artery Pulsatility Index With Adverse Cardiovascular Events Across a Hospital-Based Sample

BACKGROUND

The pulmonary artery pulsatility index (PAPi), calculated from the ratio of the pulmonary artery pulse pressure to right atrial pressure, is a predictor of right ventricular failure after inferior myocardial infarction and left ventricular assist device implantation. Whether PAPi is associated with adverse outcomes across a heterogeneous population is unknown.

METHODS

We examined consecutive patients undergoing right heart catheterization between 2005 and 2016 in a hospital-based cohort. Multivariable Cox models were utilized to examine the association between PAPi and all-cause mortality, major adverse cardiac events, and heart failure hospitalizations.

RESULTS

We studied 8285 individuals (mean age 63 years, 39% women) with median PAPi across quartiles 1.7, 2.8, 4.2, and 8.7, who were followed over a mean follow-up of 6.7±3.3 years. Patients in the lowest PAPi quartile had a 60% greater risk of death compared with the highest quartile (multivariable-adjusted hazard ratio, 1.60 [95% CI, 1.36-1.88], P<0.001) and a higher risk of major adverse cardiac events and heart failure hospitalizations (hazard ratio, 1.80 [95% CI, 1.56-2.07], P<0.001 and hazard ratio, 2.08 [95% CI, 1.76-2.47], P<0.001, respectively). Of note, patients in quartiles 2 and 3 also had increased risk of cardiovascular events compared with quartile 4 (multivariable P<0.05 for all).

CONCLUSIONS

Compared with the highest PAPi quartile, patients in PAPi quartiles 1 to 3 had a greater risk of all-cause mortality, major adverse cardiac events, and heart failure hospitalizations, with greatest risk observed in the lowest quartile. A low PAPi, even at values higher than previously reported, may serve an important role in identifying high-risk individuals across a broad spectrum of cardiovascular disease.

Arterial Stiffness and Vascular Load in HFpEF: Differences Among Women and Men

BACKGROUND

Mechanisms underlying sex differences in heart failure with preserved ejection fraction (HFpEF) are poorly understood. We sought to examine sex differences in measures of arterial stiffness and the association of arterial stiffness measures with left ventricular hemodynamic responses to exercise in men and women.

METHODS

We studied 83 men (mean age 62 years) and 107 women (mean age 59 years) with HFpEF who underwent cardiopulmonary exercise testing with invasive hemodynamic monitoring and arterial stiffness measurement (augmentation pressure [AP], augmentation index [AIx], and aortic pulse pressure [AoPP]). Sex differences were compared using multivariable linear regression. We examined the association of arterial stiffness with abnormal left ventricular diastolic response to exercise, defined as a rise in pulmonary capillary wedge pressure relative to cardiac output (∆PCWP/∆CO) ≥ 2 mmHg/L/min by using logistic regression models.

RESULTS

Women with HFpEF had increased arterial stiffness compared with men. AP was nearly 10 mmHg higher, and AIx was more than 10% higher in women compared with men (P < 0.0001 for both). Arterial stiffness measures were associated with a greater pulmonary capillary wedge pressure response to exercise, particularly among women. A 1-standard deviation higher AP was associated with > 3-fold increased odds of abnormal diastolic exercise response (AP: OR 3.16, 95% CI 1.34-7.42; P = 0.008 [women] vs OR 2.07, 95% CI 0.95-5.49; P = 0.15 [men]) with similar findings for AIx and AoPP.

CONCLUSIONS

Arterial stiffness measures are significantly higher in women with HFpEF than in men and are associated with abnormally steep increases in pulmonary capillary wedge pressure with exercise, particularly in women. Arterial stiffness may preferentially contribute to abnormal diastolic function during exercise in women with HFpEF compared with men.

Cardiovascular disease related circulating biomarkers and cancer incidence and mortality: is there an association?

AIMS

Recent studies suggest an association between cardiovascular disease (CVD) and cancer incidence/mortality, but the pathophysiological mechanisms underlying these associations are unclear. We aimed to examine biomarkers previously associated with CVD and study their association with incident cancer and cancer-related death in a prospective cohort study.

METHODS AND RESULTS

We used a proteomic platform to measure 71 cardiovascular biomarkers among 5,032 participants in the Framingham Heart Study who were free of cancer at baseline. We used multivariable-adjusted Cox models to examine the association of circulating protein biomarkers with risk of cancer incidence and mortality. To account for multiple testing, we set a 2-sided false discovery rate (FDR Q-value) <0.05.Growth differentiation factor-15 (GDF15; also known as macrophage inhibitory cytokine-1 [MIC1])) was associated with increased risk of incident cancer (hazards ratio [HR] per 1 standard deviation increment 1.31, 95% CI 1.17-1.47), incident gastrointestinal cancer (HR 1.85, 95% CI 1.37-2.50), incident colorectal cancer (HR 1.94, 95% CI 1.29-2.91) and cancer-related death (HR 2.15, 95% CI 1.72-2.70). Stromal cell-derived factor-1 (SFD1) showed an inverse association with cancer-related death (HR 0.75, 95% CI 0.65-0.86). Fibroblast growth factor-23 (FGF23) showed an association with colorectal cancer (HR 1.55, 95% CI 1.20-2.00), and granulin (GRN) was associated with hematologic cancer (HR 1.61, 95% CI 1.30-1.99). Other circulating biomarkers of inflammation, immune activation, metabolism, and fibrosis showed suggestive associations with future cancer diagnosis.

CONCLUSION

We observed several significant associations between circulating CVD biomarkers and cancer, supporting the idea that shared biological pathways underlie both diseases. Further investigations of specific mechanisms that lead to both CVD and cancer are warranted.

TRANSLATIONAL PERSPECTIVE

In our prospective cohort study, baseline levels of biomarkers previously associated with CVD were found to be associated with future development of cancer. In particular, GDF15 was associated with increased risk of cancer incidence and mortality, including gastrointestinal and colorectal cancers; SDF1 was inversely associated with cancer-related death, and FGF23 and GRN were associated with increased risk of colorectal and hematologic cancers, respectively. Other biomarkers of inflammation, immune activation, metabolism, and fibrosis showed suggestive associations. These results suggest potential shared biological pathways that underlie both development of cancer and CVD.

Association of obesity-related inflammatory pathways with lung function and exercise capacity

BACKGROUND

Obesity has multifactorial effects on lung function and exercise capacity. The contributions of obesity-related inflammatory pathways to alterations in lung function remain unclear.

RESEARCH QUESTION

To examine the association of obesity-related inflammatory pathways with pulmonary function, exercise capacity, and pulmonary-specific contributors to exercise intolerance.

METHOD

We examined 695 patients who underwent cardiopulmonary exercise testing (CPET) with invasive hemodynamic monitoring at Massachusetts General Hospital between December 2006-June 2017. We investigated the association of adiponectin, leptin, resistin, IL-6, CRP, and insulin resistance (HOMA-IR) with pulmonary function and exercise parameters using multivariable linear regression.

RESULTS

Obesity-related inflammatory pathways were associated with worse lung function. Specifically, higher CRP, IL-6, and HOMA-IR were associated with lower percent predicted FEV₁ and FVC with a preserved FEV₁/FVC ratio suggesting a restrictive physiology pattern (P ≤ 0.001 for all). For example, a 1-SD higher natural-logged CRP level was associated with a nearly 5% lower percent predicted FEV₁ and FVC (beta -4.8, s.e. 0.9 for FEV1; beta -4.9, s.e. 0.8 for FVC; P < 0.0001 for both). Obesity-related inflammatory pathways were associated with worse pulmonary vascular distensibility (adiponectin, IL-6, and CRP, P < 0.05 for all), as well as lower pulmonary artery compliance (IL-6 and CRP, P ≤ 0.01 for both).

INTERPRETATION

Our findings highlight the importance of obesity-related inflammatory pathways including inflammation and insulin resistance on pulmonary spirometry and pulmonary vascular function. Specifically, systemic inflammation as ascertained by CRP, IL-6 and insulin resistance are associated with restrictive pulmonary physiology independent of BMI. In addition, inflammatory markers were associated with lower exercise capacity and pulmonary vascular dysfunction.

Sex differences in inflammatory markers in patients hospitalized with COVID-19 infection: Insights from the MGH COVID-19 patient registry

Background

Men are at higher risk for serious complications related to COVID-19 infection than women. More robust immune activation in women has been proposed to contribute to decreased disease severity, although systemic inflammation has been associated with worse outcomes in COVID-19 infection. Whether systemic inflammation contributes to sex differences in COVID-19 infection is not known.

Study design and methods

We examined sex differences in inflammatory markers among 453 men (mean age 61) and 328 women (mean age 62) hospitalized with COVID-19 infection at the Massachusetts General Hospital from March 8 to April 27, 2020. Multivariable linear regression models were used to examine the association of sex with initial and peak inflammatory markers. Exploratory analyses examined the association of sex and inflammatory markers with 28-day clinical outcomes using multivariable logistic regression.

Results

Initial and peak CRP were higher in men compared with women after adjustment for baseline differences (initial CRP: ß 0.29, SE 0.07, p = 0.0001; peak CRP: ß 0.31, SE 0.07, p<0.0001) with similar findings for IL-6, PCT, and ferritin (p<0.05 for all). Men had greater than 1.5-greater odds of dying compared with women (OR 1.71, 95% CI 1.04–2.80, p = 0.03). Sex modified the association of peak CRP with both death and ICU admission, with stronger associations observed in men compared with women (death: OR 9.19, 95% CI 4.29–19.7, p <0.0001 in men vs OR 2.81, 95% CI 1.52–5.18, p = 0.009 in women, P_interaction = 0.02).

Conclusions

In a sample of 781 men and women hospitalized with COVID-19 infection, men exhibited more robust inflammatory activation as evidenced by higher initial and peak inflammatory markers, as well as worse clinical outcomes. Better understanding of sex differences in immune responses to COVID-19 infection may shed light on the pathophysiology of COVID-19 infection.

Divergent biochemical and enzymatic properties of oxalate oxidase isoforms encoded by four similar genes in rice

The biochemical and enzymatic properties of four highly similar rice oxalate oxidase proteins (OsOxO1-4) were compared after their purification from the leaves of transgenic plants each overexpressing the respective OsOxO1-4 genes. Although alignment of their amino acid sequences has revealed divergence mainly in the signal peptides and they catalyze the same enzymic (oxalate oxidase) reaction, divergence in apparent molecular mass, Km, optimum pH, stability and responses to inhibitors and activators was uncovered by biochemical characterization of the purified OsOxO1-4 proteins. The apparent molecular mass of oligomer OsOxO1 was found to be similar to that of OsOxO3 but lower than the other two. The molecular mass of the subunit of OsOxO1 was lower than that of OsOxO3. The Km value of OsOxO3 was higher than the other three which had similar Km. OsOxO1 and OsOxO4 possessed peak activity at pH 8.5 which was close to that at the optimum pH 4.0. The activity of OsOxO2 at pH 8.5 was only 65% of that at its optimum pH 3.5, while the activity of OsOxO3 did not vary much at pH 6-9 and was also much lower than that at its optimum pH 3. OsOxO2 and OsOxO3 still maintained all their activities after being heated at 70°C for 1h while OsOxO1 and OsOxO4 lost about 30% of their activities. Pyruvate and oxaloacetic acid inhibited the activity of OsOxO3 more strongly than the other three. Interestingly, glucose 6-phosphate, fructose 6-phosphate and fructose 1,6-biphosphate related to photosynthetic assimilation of triose phosphate greatly increased the activities of OsOxO3 and OsOxO4. In addition to the differences in the biochemical properties of the four OsOxO proteins, an intriguing finding is that the purified OsOxO1-4 exhibited substrate inhibition, which is a typical of the classical Michaelis-Menten enzyme kinetics exhibited by a majority of other enzymes.