An evidence-based screening tool for heart failure with preserved ejection fraction: the HFpEF-ABA score.

Heart failure with preserved ejection fraction (HFpEF) is under-recognized in clinical practice. Although a previously developed risk score, termed H2FPEF, can be used to estimate HFpEF probability, this score requires imaging data, which is often unavailable. Here we sought to develop an HFpEF screening model that is based exclusively on clinical variables and that can guide the need for echocardiography and further testing. In a derivation cohort (n = 414, 249 women), a clinical model using age, body mass index and history of atrial fibrillation (termed the HFpEF-ABA score) showed good discrimination (area under the curve (AUC) = 0.839 (95% confidence interval (CI) = 0.800-0.877), P < 0.0001). The performance of the model was validated in an international, multicenter cohort (n = 736, 443 women; AUC = 0.813 (95% CI = 0.779-0.847), P < 0.0001) and further validated in two additional cohorts: a cohort including patients with unexplained dyspnea (n = 228, 136 women; AUC = 0.840 (95% CI = 0.782-0.900), P < 0.0001) and a cohort for which HF hospitalization was used instead of hemodynamics to establish an HFpEF diagnosis (n = 456, 272 women; AUC = 0.929 (95% CI = 0.909-0.948), P < 0.0001). Model-based probabilities were also associated with increased risk of HF hospitalization or death among patients from the Mayo Clinic (n = 790) and a US national cohort across the Veteran Affairs health system (n = 3076, 110 women). Using the HFpEF-ABA score, rapid and efficient screening for risk of undiagnosed HFpEF can be performed in patients with dyspnea using only age, body mass index and history of atrial fibrillation.

Right Atrial Adaptation to Precapillary Pulmonary Hypertension: Pressure-Volume, Cardiomyocyte, and Histological Analysis.

BACKGROUND: Precapillary pulmonary hypertension (precPH) patients have altered right atrial (RA) function and right ventricular (RV) diastolic stiffness. OBJECTIVES: This study aimed to investigate RA function using pressure-volume (PV) loops, isolated cardiomyocyte, and histological analyses. METHODS: RA PV loops were constructed in control subjects (n = 9) and precPH patients (n = 27) using magnetic resonance and catheterization data. RA stiffness (pressure rise during atrial filling) and right atrioventricular coupling index (RA minimal volume / RV end-diastolic volume) were compared in a larger cohort of patients with moderate (n = 39) or severe (n = 41) RV diastolic stiffness. Cardiomyocytes were isolated from RA tissue collected from control subjects (n = 6) and precPH patients (n = 9) undergoing surgery. Autopsy material was collected from control subjects (n = 6) and precPH patients (n = 4) to study RA hypertrophy, capillarization, and fibrosis. RESULTS: RA PV loops showed 3 RA cardiac phases (reservoir, passive emptying, and contraction) with dilatation and elevated pressure in precPH. PrecPH patients with severe RV diastolic stiffness had increased RA stiffness and worse right atrioventricular coupling index. Cardiomyocyte cross-sectional area was increased 2- to 3-fold in precPH, but active tension generated by the sarcomeres was unaltered. There was no increase in passive tension of the cardiomyocytes, but end-stage precPH showed reduced number of capillaries per mm2 accompanied by interstitial and perivascular fibrosis. CONCLUSIONS: RA PV loops show increased RA stiffness and suggest atrioventricular uncoupling in patients with severe RV diastolic stiffness. Isolated RA cardiomyocytes of precPH patients are hypertrophied, without intrinsic sarcomeric changes. In end-stage precPH, reduced capillary density is accompanied by interstitial and perivascular fibrosis.

Trimetazidine in heart failure with preserved ejection fraction: a randomized controlled cross-over trial.

AIMS: Impaired myocardial energy homeostasis plays an import role in the pathophysiology of heart failure with preserved ejection fraction (HFpEF). Left ventricular relaxation has a high energy demand, and left ventricular diastolic dysfunction has been related to impaired energy homeostasis. This study investigated whether trimetazidine, a fatty acid oxidation inhibitor, could improve myocardial energy homeostasis and consequently improve exercise haemodynamics in patients with HFpEF. METHODS AND RESULTS: The DoPING-HFpEF trial was a phase II single-centre, double-blind, placebo-controlled, randomized cross-over trial. Patients were randomized to trimetazidine treatment or placebo for 3 months and switched after a 2-week wash-out period. The primary endpoint was change in pulmonary capillary wedge pressure, measured with right heart catheterization at multiple stages of bicycling exercise. Secondary endpoint was change in myocardial phosphocreatine/adenosine triphosphate, an index of the myocardial energy status, measured with phosphorus-31 magnetic resonance spectroscopy. The study included 25 patients (10/15 males/females; mean (standard deviation) age, 66 (10) years; body mass index, 29.8 (4.5) kg/m2 ); with the diagnosis of HFpEF confirmed with (exercise) right heart catheterization either before or during the trial. There was no effect of trimetazidine on the primary outcome pulmonary capillary wedge pressure at multiple levels of exercise (mean change 0 [95% confidence interval, 95% CI -2, 2] mmHg over multiple levels of exercise, P = 0.60). Myocardial phosphocreatine/adenosine triphosphate in the trimetazidine arm was similar to placebo (1.08 [0.76, 1.76] vs. 1.30 [0.95, 1.86], P = 0.08). There was no change by trimetazidine compared with placebo in the exploratory parameters: 6-min walking distance (mean change of -6 [95% CI -18, 7] m vs. -5 [95% CI -22, 22] m, respectively, P = 0.93), N-terminal pro-B-type natriuretic peptide (5 (-156, 166) ng/L vs. -13 (-172, 147) ng/L, P = 0.70), overall quality-of-life (KCCQ and EQ-5D-5L, P = 0.78 and P = 0.51, respectively), parameters for diastolic function measured with echocardiography and cardiac magnetic resonance, or metabolic parameters. CONCLUSIONS: Trimetazidine did not improve myocardial energy homeostasis and did not improve exercise haemodynamics in patients with HFpEF.

Right Ventricular Function During Exercise After Pulmonary Endarterectomy for Chronic Thromboembolic Pulmonary Hypertension.

Background Pulmonary endarterectomy (PEA) for chronic thromboembolic pulmonary hypertension improves resting hemodynamics and right ventricular (RV) function. Because exercise tolerance frequently remains impaired, RV function may not have completely normalized after PEA. Therefore, we performed a detailed invasive hemodynamic study to investigate the effect of PEA on RV function during exercise. Methods and Results In this prospective study, all consenting patients with chronic thromboembolic pulmonary hypertension eligible for surgery and able to perform cycle ergometry underwent cardiac magnetic resonance imaging, a maximal cardiopulmonary exercise test, and a submaximal invasive cardiopulmonary exercise test before and 6 months after PEA. Hemodynamic assessment and analysis of RV pressure curves using the single-beat method was used to determine load-independent RV contractility (end systolic elastance), RV afterload (arterial elastance), RV-arterial coupling (end systolic elastance-arterial elastance), and stroke volume both at rest and during exercise. RV rest-to-exercise responses were compared before and after PEA using 2-way repeated-measures analysis of variance with Bonferroni post hoc correction. A total of 19 patients with chronic thromboembolic pulmonary hypertension completed the entire study protocol. Resting hemodynamics improved significantly after PEA. The RV exertional stroke volume response improved 6 months after PEA (79±32 at rest versus 102±28 mL during exercise; P<0.01). Although RV afterload (arterial elastance) increased during exercise, RV contractility (end systolic elastance) did not change during exercise either before (0.43 [0.32-0.58] mm Hg/mL versus 0.45 [0.22-0.65] mm Hg/mL; P=0.6) or after PEA (0.32 [0.23-0.40] mm Hg/mL versus 0.28 [0.19-0.44] mm Hg/mL; P=0.7). In addition, mean pulmonary artery pressure-cardiac output and end systolic elastance-arterial elastance slopes remained unchanged after PEA. Conclusions The exertional RV stroke volume response improves significantly after PEA for chronic thromboembolic pulmonary hypertension despite a persistently abnormal afterload and absence of an RV contractile reserve. This may suggest that at mildly elevated pulmonary pressures, stroke volume is less dependent on RV contractility and afterload and is primarily determined by venous return and conduit function.

Inflammation and heart failure: a two-sample Mendelian randomization study.

BACKGROUND: It is hypothesized that inflammation leads to heart failure. Results from observational studies thus far have been inconsistent and it is unclear whether inflammation is causally associated with new-onset heart failure. Mendelian randomization analyses are less prone to biases common in observational studies such as reverse causation and unmeasured confounding. The aim of this study was to investigate the causal relation between various inflammatory biomarkers with risk of new-onset heart failure by using a two-sample Mendelian randomization approach. METHODS: Ten inflammatory biomarkers with available genome-wide association studies (GWAS) among individuals of European ancestry were identified and included C-reactive protein (CRP), immunoglobulin E, tumour necrosis factor (TNF), toll-like receptor 4, interleukin 1 receptor antagonist, interleukin 2 receptor subunit α, interleukin 6 receptor subunit α, interleukin 16, 17 and 18. For the associations between the identified SNPs and heart failure, we used the largest GWAS meta-analysis performed by the Heart Failure Molecular Epidemiology for Therapeutic Targets Consortium with 47 309 participants with heart failure and 930 014 controls. For our main analyses, we used the inverse-variance weighted method. RESULTS: We included 63 SNPs. CRP, TNF, interleukin 2, 16 and 18 were not associated with heart failure with odds ratios (ORs) of 1.01 [95% confidence interval (95% CI: 0.94-1.09), 1.11 (95% CI: 0.80-1.48), 0.97 (95% CI: 0.93-1.02), 0.99 (95% CI: 0.96-1.03) and 1.01 (95% CI: 0.97-1.06), respectively. The other biomarkers were also not associated with the risk of heart failure and suffered from weak instrument bias. CONCLUSION: This Mendelian randomization study could not determine a causal relationship between inflammation and risk of heart failure. However, some biomarkers suffered from weak instrument bias.

Sex differences in the longitudinal relationship of low-grade inflammation and echocardiographic measures in the Hoorn and FLEMENGHO Study.

BACKGROUND: This study aimed to determine the within-person and between-persons associations of low-grade inflammation (LGI) and endothelial dysfunction (ED) with echocardiographic measures related to diastolic dysfunction (DD) in two general populations and whether these associations differed by sex. METHODS: Biomarkers and echocardiographic measures were measured at both baseline and follow-up in the Hoorn Study (n = 383) and FLEMENGHO (n = 491). Individual biomarker levels were combined into either a Z-score of LGI (CRP, SAA, IL-6, IL-8, TNF-α and sICAM-1) or ED (sICAM-1, sVCAM-1, sE-selectin and sTM). Mixed models were used to determine within-person and between-persons associations of biomarker Z-scores with left ventricular ejection fraction (LVEF), left ventricular mass index (LVMI) and left atrial volume index (LAVI). These associations were adjusted for a-priori selected confounders. RESULTS: Overall Z-scores for LGI or ED were not associated with echocardiographic measures. Effect modification by sex was apparent for ED with LVEF in both cohorts (P-for interaction = 0.08 and 0.06), but stratified results were not consistent. Effect modification by sex was apparent for TNF-α in the Hoorn Study and E-selectin in FLEMENGHO with LVEF (P-for interaction≤0.05). In the Hoorn Study, women whose TNF-α levels increased with 1-SD over time had a decrease in LVEF of 2.2 (-4.5;0.01) %. In FLEMENGHO, men whose E-selectin levels increased with 1-SD over time had a decrease in LVEF of 1.6 (-2.7;-0.5) %. CONCLUSION: Our study did not show consistent associations of LGI and ED with echocardiographic measures. Some evidence of effect modification by sex was present for ED and specific biomarkers.

The Effect of Anti-TNF Therapy on Cardiac Function in Rheumatoid Arthritis: An Observational Study.

Congestive heart failure (CHF) is the second most prevalent cause of death in rheumatoid arthritis (RA). The systemic inflammatory state in RA patients is deemed responsible for this finding. Anti-inflammatory treatment with anti-tumor necrosis factor (anti-TNF) therapy decreases CV risk and subsequently might improve the cardiac function by lowering the overall inflammatory state. This study investigated the effect of anti-TNF on the cardiac function in RA patients. Fifty one RA patients were included, of which thirty three completed follow-up. Included patients were >18 years, had moderate-high disease activity and no history of cardiac disease. Patients were assessed at baseline and after six months of anti-TNF treatment. Patients underwent conventional Speckle tracking and tissue Doppler echocardiography in combination with clinical and laboratory assessments at baseline and follow-up. The left ventricular ejection fraction (LVEF) and global longitudinal strain (GLS) showed no changes during follow-up, LVEF 63% (±9) to 62% (±8) p = 0.097 and GLS -20 (±4) to -20 (±3) p = 0.79, respectively. Furthermore, E/e' nor E/A changed significantly between baseline and follow-up, respectively 8 (7-9) and 8 (7-9) p = 0.17 and 1.1 (±0.4) and 1.1 (±0.4) p = 0.94. Follow-up NT-proBNP decreased with 23%, from 89 ng/L (47-142) to 69 ng/L (42-155), p = 0.10. Regression analysis revealed no association between change in inflammatory variables and cardiac function. Echocardiography showed no effect of anti-TNF treatment on the cardiac function in RA patients with low prevalence of cardiac dysfunction. Moreover, NT-proBNP decreased, possibly indicating (subtle) improvement of the cardiac function.

Noninvasive Prediction of Elevated Wedge Pressure in Pulmonary Hypertension Patients Without Clear Signs of Left-Sided Heart Disease: External Validation of the OPTICS Risk Score.

Background Although most newly presenting patients with pulmonary hypertension (PH) have elevated pulmonary artery wedge pressure, identification of so-called postcapillary PH can be challenging. A noninvasive tool predicting elevated pulmonary artery wedge pressure in patients with incident PH may help avoid unnecessary invasive diagnostic procedures. Methods and Results A combination of clinical data, ECG, and echocardiographic parameters was used to refine a previously developed left heart failure risk score in a retrospective cohort of pre- and postcapillary PH patients. This updated score (renamed the OPTICS risk score) was externally validated in a prospective cohort of patients from 12 Dutch nonreferral centers the OPTICS network. Using the updated OPTICS risk score, the presence of postcapillary PH could be predicted on the basis of body mass index ≥30, diabetes mellitus, atrial fibrillation, dyslipidemia, history of valvular surgery, sum of SV1 (deflection in V1 in millimeters) and RV6 (deflection in V6 in millimeters) on ECG, and left atrial dilation. The external validation cohort included 81 postcapillary PH patients and 66 precapillary PH patients. Using a predefined cutoff of >104, the OPTICS score had 100% specificity for postcapillary PH (sensitivity, 22%). In addition, we investigated whether a high probability of heart failure with preserved ejection fraction, assessed by the H2FPEF score (obesity, atrial fibrillation, age >60 yrs, ≥2 antihypertensives, E/e' >9, and pulmonary artery systolic pressure by echo >35 mmHg), similarly predicted the presence of elevated pulmonary artery wedge pressure. High probability of heart failure with preserved ejection fraction (H2FPEF score ≥6) was less specific for postcapillary PH. Conclusions In a community setting, the OPTICS risk score can predict elevated pulmonary artery wedge pressure in PH patients without clear signs of left-sided heart disease. The OPTICS risk score may be used to tailor the decision to perform invasive diagnostic testing.

Modifiable lifestyle factors and heart failure: A Mendelian randomization study.

BACKGROUND: Lifestyle factors may be important targets in the prevention of heart failure. The current knowledge on the relationship between lifestyle factors and heart failure originates mostly from observational studies. The objective of this study was to investigate causal associations of multiple lifestyle factors with heart failure risk by using Mendelian randomization. METHODS: We obtained summary statistics data for single nucleotide polymorphisms associated with the following 5 lifestyle factors at genome-wide significance in genome-wide association studies of European-descent individuals: smoking, alcohol consumption, coffee consumption, physical activity, and sleep duration. The corresponding data for heart failure were acquired from a genome-wide association study comprising 47,309 cases and 930,014 controls of European ancestry. For the primary analyses, we used the inverse-variance weighted method. RESULTS: Genetic predisposition to smoking initiation (ever smoked regularly) was robustly associated with a higher odds of heart failure (odds ratio: 1.28; 99% CI: 1.21-1.35). Genetically predicted longer sleep duration was associated with a lower odds of heart failure (odds ratio per hour/day: 0.73; 99% CI: 0.60-0.89). We found no associations of alcohol consumption, coffee consumption, and physical activity with heart failure. CONCLUSIONS: This Mendelian randomization study showed that smoking initiation increases heart failure risk, whereas longer sleep duration decreases the risk of heart failure. Sleep duration should be regarded as novel risk factor in heart failure prevention guidelines. The potential causal role of alcohol and coffee consumption and physical activity for heart failure warrants further investigation in future larger Mendelian randomization analyses.

The relevance of a multidomain geriatric assessment in older patients with heart failure.

AIMS: Physical frailty screening is more commonly performed at outpatient heart failure (HF) clinics. However, this does not incorporate other common geriatric domains. This study assesses whether a multidomain geriatric assessment, in comparison with HF severity or physical frailty, is associated with short-term adverse outcomes. METHODS AND RESULTS: This is a prospective cohort study of 197 patients with HF (mean age 78, 44% female) attending outpatient HF clinics. HF severity was assessed with New York Heart Association class (I-II versus III-IV) and N-terminal pro b-type natriuretic peptide levels. Physical frailty was assessed with the Fried frailty criteria (not frail, pre-frail, and frail). The following geriatric domains were assessed: physical function, nutrition, polypharmacy, cognition, and dependency in activities of daily living. Logistic regression analyses adjusted for age, sex, diabetes and kidney function assessed 3 month risk of adverse health outcomes (emergency department visits, hospital admissions, and/or death) according to HF severity, physical frailty, and number of affected domains. Number (%) of patients with HF with no, 1, 2, and ≥3 domains affected were 36 (18%), 61 (31%), 58 (29%), and 42 (21%). Seventy-four adverse outcomes were experienced in 50 patients at follow-up. Severity of HF and physical frailty were not significantly associated with an increased risk of adverse health outcomes. However, increasing number of affected domains were significantly associated with an increased risk of adverse outcomes. Compared with no domains affected, odds ratios (95% confidence interval) for 1, 2, and ≥3 domains were 1.8 (0.5-6.5), 4.5 (1.3-15.4), and 7.2 (2.0-26.3) (P-trend <0.01). Further adjustment for HF severity and frailty status slightly attenuated the effect estimates (P-trend 0.02). CONCLUSIONS: Having limitations in multiple domains appears more strongly associated with short-term adverse outcomes than HF severity and physical frailty. This may illustrate the potential added value of a multidomain geriatric assessment in the evaluation and treatment of patients with HF with respect to relevant short-term health outcomes.

Right Ventricular Myocardial Stiffness in Experimental Pulmonary Arterial Hypertension: Relative Contribution of Fibrosis and Myofibril Stiffness.

BACKGROUND: The purpose of this study was to determine the relative contribution of fibrosis-mediated and myofibril-mediated stiffness in rats with mild and severe right ventricular (RV) dysfunction. METHODS AND RESULTS: By performing pulmonary artery banding of different diameters for 7 weeks, mild RV dysfunction (Ø=0.6 mm) and severe RV dysfunction (Ø=0.5 mm) were induced in rats. The relative contribution of fibrosis- and myofibril-mediated RV stiffness was determined in RV trabecular strips. Total myocardial stiffness was increased in trabeculae from both mild and severe RV dysfunction in comparison to controls. In severe RV dysfunction, increased RV myocardial stiffness was explained by both increased fibrosis-mediated stiffness and increased myofibril-mediated stiffness, whereas in mild RV dysfunction, only myofibril-mediated stiffness was increased in comparison to control. Histological analyses revealed that RV fibrosis gradually increased with severity of RV dysfunction, whereas the ratio of collagen I/III expression was only elevated in severe RV dysfunction. Stiffness measurements in single membrane-permeabilized RV cardiomyocytes demonstrated a gradual increase in RV myofibril stiffness, which was partially restored by protein kinase A in both mild and severe RV dysfunction. Increased expression of compliant titin isoforms was observed only in mild RV dysfunction, whereas titin phosphorylation was reduced in both mild and severe RV dysfunction. CONCLUSIONS: RV myocardial stiffness is increased in rats with mild and severe RV dysfunction. In mild RV dysfunction, stiffness is mainly determined by increased myofibril stiffness. In severe RV dysfunction, both myofibril- and fibrosis-mediated stiffness contribute to increased RV myocardial stiffness.

Protein changes contributing to right ventricular cardiomyocyte diastolic dysfunction in pulmonary arterial hypertension.

BACKGROUND: Right ventricular (RV) diastolic function is impaired in patients with pulmonary arterial hypertension (PAH). Our previous study showed that elevated cardiomyocyte stiffness and myofilament Ca(2+) sensitivity underlie diastolic dysfunction in PAH. This study investigates protein modifications contributing to cellular diastolic dysfunction in PAH. METHODS AND RESULTS: RV samples from PAH patients undergoing heart-lung transplantation were compared to non-failing donors (Don). Titin stiffness contribution to RV diastolic dysfunction was determined by Western-blot analyses using antibodies to protein-kinase-A (PKA), Cα (PKCα) and Ca(2+)/calmoduling-dependent-kinase (CamKIIδ) titin and phospholamban (PLN) phosphorylation sites: N2B (Ser469), PEVK (Ser170 and Ser26), and PLN (Thr17), respectively. PKA and PKCα sites were significantly less phosphorylated in PAH compared with donors (P<0.0001). To test the functional relevance of PKA-, PKCα-, and CamKIIδ-mediated titin phosphorylation, we measured the stiffness of single RV cardiomyocytes before and after kinase incubation. PKA significantly decreased PAH RV cardiomyocyte diastolic stiffness, PKCα further increased stiffness while CamKIIδ had no major effect. CamKIIδ activation was determined indirectly by measuring PLN Thr17phosphorylation level. No significant changes were found between the groups. Myofilament Ca(2+) sensitivity is mediated by sarcomeric troponin I (cTnI) phosphorylation. We observed increased unphosphorylated cTnI in PAH compared with donors (P<0.05) and reduced PKA-mediated cTnI phosphorylation (Ser22/23) (P<0.001). Finally, alterations in Ca(2+)-handling proteins contribute to RV diastolic dysfunction due to insufficient diastolic Ca(2+) clearance. PAH SERCA2a levels and PLN phosphorylation were significantly reduced compared with donors (P<0.05). CONCLUSIONS: Increased titin stiffness, reduced cTnI phosphorylation, and altered levels of phosphorylation of Ca(2+) handling proteins contribute to RV diastolic dysfunction in PAH.

Syphilis: a reversible cause of nephrotic syndrome.

A patient in his late 30s presented with symptoms consistent with a nephrotic syndrome. Renal biopsy revealed membranous nephropathy. He also mentioned a spontaneous resolving 'rash' at his glans penis after unprotected intercourse. Therefore, he was tested for sexually transmitted diseases as a possible underlying cause of his nephrotic syndrome. Serology for syphilis was positive with high titres. After a single penicillin injection, there was fast and complete clinical recovery.

Dysregulated renin-angiotensin-aldosterone system contributes to pulmonary arterial hypertension.

RATIONALE: Patients with idiopathic pulmonary arterial hypertension (iPAH) often have a low cardiac output. To compensate, neurohormonal systems such as the renin-angiotensin-aldosterone system (RAAS) and the sympathetic nervous system are up-regulated, but this may have long-term negative effects on the progression of iPAH. OBJECTIVES: Assess systemic and pulmonary RAAS activity in patients with iPAH and determine the efficacy of chronic RAAS inhibition in experimental PAH. METHODS: We collected 79 blood samples from 58 patients with iPAH in the VU University Medical Center Amsterdam (between 2004 and 2010) to determine systemic RAAS activity. MEASUREMENTS AND MAIN RESULTS: We observed increased levels of renin, angiotensin (Ang)I, and AngII, which were associated with disease progression (P < 0.05) and mortality (P < 0.05). To determine pulmonary RAAS activity, lung specimens were obtained from patients with iPAH (during lung transplantation, n = 13) and control subjects (during lobectomy or pneumonectomy for cancer, n = 14). Local RAAS activity in pulmonary arteries of patients with iPAH was increased, demonstrated by elevated angiotensin-converting enzyme activity in pulmonary endothelial cells and increased AngII type 1 (AT(1)) receptor expression and signaling. In addition, local RAAS up-regulation was associated with increased pulmonary artery smooth muscle cell proliferation via enhanced AT(1) receptor signaling in patients with iPAH compared with control subjects. Finally, to determine the therapeutic potential of RAAS activity, we assessed the chronic effects of an AT(1) receptor antagonist (losartan) in the monocrotaline PAH rat model (60 mg/kg). Losartan delayed disease progression, decreased right ventricular afterload and pulmonary vascular remodeling, and restored right ventricular-arterial coupling in rats with PAH. CONCLUSIONS: Systemic and pulmonary RAAS activities are increased in patients with iPAH and are associated with increased pulmonary vascular remodeling. Chronic inhibition of RAAS by losartan is beneficial in experimental PAH.

Diastolic stiffness of the failing diabetic heart: importance of fibrosis, advanced glycation end products, and myocyte resting tension.

BACKGROUND: Excessive diastolic left ventricular stiffness is an important contributor to heart failure in patients with diabetes mellitus. Diabetes is presumed to increase stiffness through myocardial deposition of collagen and advanced glycation end products (AGEs). Cardiomyocyte resting tension also elevates stiffness, especially in heart failure with normal left ventricular ejection fraction (LVEF). The contribution to diastolic stiffness of fibrosis, AGEs, and cardiomyocyte resting tension was assessed in diabetic heart failure patients with normal or reduced LVEF. METHODS AND RESULTS: Left ventricular endomyocardial biopsy samples were procured in 28 patients with normal LVEF and 36 patients with reduced LVEF, all without coronary artery disease. Sixteen patients with normal LVEF and 10 with reduced LVEF had diabetes mellitus. Biopsy samples were used for quantification of collagen and AGEs and for isolation of cardiomyocytes to measure resting tension. Diabetic heart failure patients had higher diastolic left ventricular stiffness irrespective of LVEF. Diabetes mellitus increased the myocardial collagen volume fraction only in patients with reduced LVEF (from 14.6+/-1.0% to 22.4+/-2.2%, P<0.001) and increased cardiomyocyte resting tension only in patients with normal LVEF (from 5.1+/-0.7 to 8.5+/-0.9 kN/m2, P=0.006). Diabetes increased myocardial AGE deposition in patients with reduced LVEF (from 8.8+/-2.5 to 24.1+/-3.8 score/mm2; P=0.005) and less so in patients with normal LVEF (from 8.2+/-2.5 to 15.7+/-2.7 score/mm2, P=NS). CONCLUSIONS: Mechanisms responsible for the increased diastolic stiffness of the diabetic heart differ in heart failure with reduced and normal LVEF: Fibrosis and AGEs are more important when LVEF is reduced, whereas cardiomyocyte resting tension is more important when LVEF is normal.