Pulmonary hypertension in chronic heart failure: definitions, advances, and unanswered issues

Simultaneous Positron Emission Tomography and Molecular Magnetic Resonance Imaging of Cardiopulmonary Fibrosis in a Mouse Model of Left Ventricular Dysfunction

BACKGROUND

Aging-associated left ventricular dysfunction promotes cardiopulmonary fibrogenic remodeling, Group 2 pulmonary hypertension (PH), and right ventricular failure. At the time of diagnosis, cardiac function has declined, and cardiopulmonary fibrosis has often developed. Here, we sought to develop a molecular positron emission tomography (PET)-magnetic resonance imaging (MRI) protocol to detect both cardiopulmonary fibrosis and fibrotic disease activity in a left ventricular dysfunction model.

METHODS AND RESULTS

Left ventricular dysfunction was induced by transverse aortic constriction (TAC) in 6-month-old senescence-accelerated prone mice, a subset of mice that received sham surgery. Three weeks after surgery, mice underwent simultaneous PET-MRI at 4.7 T. Collagen-targeted PET and fibrogenesis magnetic resonance (MR) probes were intravenously administered. PET signal was computed as myocardium- or lung-to-muscle ratio. Percent signal intensity increase and Δ lung-to-muscle ratio were computed from the pre-/postinjection magnetic resonance images. Elevated allysine in the heart (P=0.02) and lungs (P=0.17) of TAC mice corresponded to an increase in myocardial magnetic resonance imaging percent signal intensity increase (P<0.0001) and Δlung-to-muscle ratio (P<0.0001). Hydroxyproline in the heart (P<0.0001) and lungs (P<0.01) were elevated in TAC mice, which corresponded to an increase in heart (myocardium-to-muscle ratio, P=0.02) and lung (lung-to-muscle ratio, P<0.001) PET measurements. Pressure-volume loop and echocardiography demonstrated adverse left ventricular remodeling, function, and increased right ventricular systolic pressure in TAC mice.

CONCLUSIONS

Administration of collagen-targeted PET and allysine-targeted MR probes led to elevated PET-magnetic resonance imaging signals in the myocardium and lungs of TAC mice. The study demonstrates the potential to detect fibrosis and fibrogenesis in cardiopulmonary disease through a dual molecular PET-magnetic resonance imaging protocol.

Lung water density is increased in patients at risk of heart failure and is largely independent of conventional cardiovascular magnetic resonance measures

Aims

Non-invasive methods to quantify pulmonary congestion are lacking in clinical practice. Cardiovascular magnetic resonance (CMR) lung water density (LWD) mapping is accurate and reproducible and has prognostic value. However, it is not known whether LWD is associated with routinely acquired CMR parameters.

Methods and results

This was an observational cohort including healthy controls and patients at risk of heart failure. LWD was measured using CMR with a free-breathing short echo time 3D Cartesian gradient-echo sequence with a respiratory navigator at 1.5 T. Associations were assessed between LWD, lung water volume and cardiac volumes, left ventricular (LV) mass and function, myocardial native T1, and extracellular volume fraction. In patients at risk for heart failure (n = 155), LWD was greater than in healthy controls (n = 15) (30.4 ± 5.0 vs. 27.2 ± 4.3%, P = 0.02). Using receiver operating characteristic analysis, the optimal cut-off for LWD was 27.6% to detect at-risk patients (sensitivity 72%, specificity 73%, positive likelihood ratio 2.7, and inverse negative likelihood ratio 2.6). LWD was univariably associated with body mass index (BMI), hypertension, right atrial area, and LV mass. In multivariable linear regression, only BMI remained associated with LWD (R 2 = 0.32, P < 0.001).

Conclusion

LWD is increased in patients at risk for heart failure compared with controls and is only weakly explained by conventional CMR measures. LWD provides diagnostic information that is largely independent of conventional CMR measures.

Practical Guidance for Hemodynamic Assessment by Right Heart Catheterization in Management of Heart Failure

Heart failure is a clinical syndrome characterized by the inability of the heart to meet the circulatory demands of the body without requiring an increase in intracardiac pressures at rest or with exertion. Hemodynamic parameters can be measured via right heart catheterization, which has an integral role in the full spectrum of heart failure: from ambulatory patients to those in cardiogenic shock, as well as patients being considered for left ventricular device therapy and heart transplantation. Hemodynamic data are critical for prompt recognition of clinical deterioration, assessment of prognosis, and guidance of treatment decisions. This review is a field guide for hemodynamic assessment, troubleshooting, and interpretation for clinicians treating patients with heart failure.

Combined Inhibition of Phosphodiesterase-5 and -9 in Experimental Heart Failure

BACKGROUND

Intracellular second messenger cyclic guanosine monophosphate (cGMP) mediates bioactivity of the natriuretic peptides and nitric oxide, and is key to circulatory homeostasis and protection against cardiovascular disease. Inhibition of cGMP-degrading phosphodiesterases (PDEs) PDE5 and PDE9 are emerging as pharmacological targets in heart failure (HF).

OBJECTIVES

The present study investigated dual enhancement of cGMP in experimental HF by combining inhibition of PDE-5 (P5-I) and PDE-9 (P9-I).

METHODS

Eight sheep with pacing-induced HF received on separate days intravenous P5-I (sildenafil), P9-I (PF-04749982), P5-I+P9-I, and vehicle control, in counterbalanced order.

RESULTS

Compared with control, separate P5-I and P9-I significantly increased circulating cGMP concentrations in association with reductions in mean arterial pressure (MAP), left atrial pressure (LAP), and pulmonary arterial pressure (PAP), with effects of P5-I on cGMP, MAP, and PAP greater than those of P9-I. Only P5-I decreased pulmonary vascular resistance. Combination P5-I+P9-I further reduced MAP, LAP, and PAP relative to inhibition of either phosphodiesterase alone. P9-I and, especially, P5-I elevated urinary cGMP levels relative to control. However, whereas inhibition of either enzyme increased urine creatinine excretion and clearance, only P9-I induced a significant diuresis and natriuresis. Combined P5-I+P9-I further elevated urine cGMP with concomitant increases in urine volume, sodium and creatinine excretion, and clearance similar to P9-I alone, despite the greater MAP reductions induced by combination treatment.

CONCLUSIONS

Combined P5-I+P9-I amalgamated the superior renal effects of P9-I and pulmonary effects of P5-1, while concurrently further reducing cardiac preload and afterload. These findings support combination P5-I+P9-I as a therapeutic strategy in HF.

Importance of heart failure duration for development of pulmonary hypertension in advanced heart failure

BACKGROUND AND OBJECTIVES

Pulmonary vascular resistance (PVR) is critical when evaluating candidacy for advanced heart failure (HF) therapies, but risk factors for elevated PVR are not well studied. We hypothesized that HF duration would be associated with elevated PVR.

METHODS

Danish single-center registry of consecutive in- and outpatients undergoing right heart catheterization as part of advanced HF work up. The relation between HF duration and PVR was estimated by regression analysis. Finally, the relation between PVR and long-term mortality was assessed by Cox proportional hazards regression and Kaplan-Meier analyses.

RESULTS

A total of 549 patients (77% men, median age 54 (43-61) years, median HF duration 1.6 years (0.1-7.1)) were included. Univariate linear regression displayed an association between longer HF duration and increasing PVR (p = 0.014). PVR > 3 WU was present in 92 patients (17%) who were older (median p < 0.001) and had longer HF duration (p = 0.03). HF duration (per 1 year increase) did not predict PVR > 3 WU after adjustment for covariables (OR 1.00; p = 0.99). During a mean follow-up time of 4.5 years, there were 240 (44%) deaths. Increasing PVR was associated with elevated all-cause mortality risk (adjusted HR 1.24; p < 0.001). PVR > 3 WU was associated with higher mortality (adjusted HR 1.49; p = 0.027).

CONCLUSION

Longer duration of HF was associated with higher PVR in patients with advanced HF, but this association disappeared in multivariate analyses. Longer HF duration per se likely does not cause elevated PVR and should not discourage evaluation for heart transplantation.

Transcatheter valvular therapies in patients with left ventricular assist devices

Aortic, mitral and tricuspid valve regurgitation are commonly encountered in patients with continuous-flow left ventricular assist devices (CF-LVADs). These valvular heart conditions either develop prior to CF-LVAD implantation or are induced by the pump itself. They can all have significant detrimental effects on patients' survival and quality of life. With the improved durability of CF-LVADs and the overall rise in their volume of implants, an increasing number of patients will likely require a valvular heart intervention at some point during CF-LVAD therapy. However, these patients are often considered poor reoperative candidates. In this context, percutaneous approaches have emerged as an attractive "off-label" option for this patient population. Recent data show promising results, with high device success rates and rapid symptomatic improvements. However, the occurrence of distinct complications such as device migration, valve thrombosis or hemolysis remain of concern. In this review, we will present the pathophysiology of valvular heart disease in the setting of CF-LVAD support to help us understand the underlying rationale of these potential complications. We will then outline the current recommendations for the management of valvular heart disease in patients with CF-LVAD and discuss their limitations. Lastly, we will summarize the evidence related to transcatheter heart valve interventions in this patient population.

The effects of severe functional mitral regurgitation on right ventricular function in patients with advanced heart failure who were on waiting list for heart transplant

Background

This study aims to investigate the effects of severe functional mitral regurgitation on the parameters that reflect right ventricular function such as tricuspid annular plane systolic excursion and right ventricular stroke work index in potential heart transplant recipients.

Methods

Between January 2015 and January 2017, a total of 282 consecutive patients (250 males, 32 females; mean age: 46±10 years; range, 18 to 66 years) with advanced heart failure who were referred for heart transplantation were retrospectively analyzed. The patients were divided into two groups as severe (n=84) and non-severe functional mitral regurgitation (n=198). Patients" medical histories, demographic characteristics, echocardiographic evaluations, and findings of right heart catheterization were recorded.

Results

The two groups were similar in terms of left ventricular ejection fraction, the New York Heart Association functional class, Interagency Registry for Mechanically Assisted Circulatory Support profile, and the duration of heart failure (p>0.05). Both groups were also similar with respect to tricuspid annular plane systolic excursion and right ventricular stroke work index. Functional mitral regurgitation was the only statistically significant variable in the univariate analysis for tricuspid annular plane systolic excursion (odds ratio [OR]: 0.58; 95% confidence interval [CI] 0.34-0.97; p=0.04), with no significant effect in the multivariate analysis. In the univariate analysis for right ventricular stroke work index, pulmonary arterial systolic pressure (OR: 0.77; 95% CI 0.67-0.88; p<0.001) was a significant variable and also had a significant effect in the multivariate analysis (OR: 0.92; 95% CI 0.87-0.97; p=0.003). In the tertile analyses, there were no significant differences between the two groups with respect to tricuspid annular plane systolic excursion and right ventricular stroke work index.

Conclusion

We found no significant difference in right ventricular functions between the severe and non-severe functional mitral regurgitation groups in patients with advanced heart failure who had relatively short follow-up. Right ventricle can maintain its normal function at early stage. Adaptive remodeling of right ventricle may have an effect on these findings. Severe functional mitral regurgitation may be associated with adverse effects on advanced heart failure by increasing the right ventricular afterload.

Diagnostic Value and Clinical Performance of Cardiac Ultrasound in Patients with Chronic Heart Failure with Hypertension

Objective

To assess the diagnostic value and clinical performance of cardiac ultrasound in patients with chronic heart failure and hypertension.

Methods

In this prospective study, between August 2017 and January 2020, 50 patients with chronic heart failure and hypertension were recruited and assigned to the study group and 50 healthy individuals during the same period after physical examinations were included in the control group. Cardiac ultrasound examinations were performed on the participants, and the results were compared and analyzed.

Results

The study group had a higher left ventricular end-diastolic diameter (LVEDD), left ventricular end-systolic diameter (LVESD), left ventricular ejection fraction (LVEF), and late diastolic peak flow velocity (A wave) and showed lower early diastolic peak flow velocity (E wave) and late diastolic peak flow velocity/lower early diastolic peak flow velocity (E/A) ratio levels than in the control group. The study group had 15 patients with grade I cardiac function (ultrasound detection rate of 100%), 18 patients with grade II cardiac function (ultrasound detection rate of 100%), and 17 patients with grade III cardiac function (ultrasound detection rate of 100%). Grade I cardiac function patients showed the lowest LVEDD, LVESD, and E/A and the highest LVEF than grade II patients, followed by grade III patients. The study group showed higher LVEF and echocardiographic estimation of the pulmonary arterial systolic pressure (PASP) and lower right ventricular lateral wall systolic excursion velocity and tricuspid annular plane systolic excursion (TAPSE) than the control group. Chronic heart failure with hypertension was associated with high levels of right atrial total emptying volume (RAVIt), right atrial passive emptying volume (RAVIp), right atrial active emptying volume (RAVIa), and right atrial active emptying fraction (RAVIaEF) and low levels of right atrial total emptying fraction (RAVItEF) and right atrial passive emptying fraction (RAVIpEF) versus the healthy status (all P < 0.05).

Conclusion

Cardiac ultrasound is a noninvasive operation with low cost, high repeatability, and accurate detection, which can identify right heart function impairment at an early stage, assist clinical treatment, and improve patient prognosis, so it is worthy of promotion and application.

Left atrial unloading with an 8 mm septal cutting balloon to treat postcapillary pulmonary hypertension: a case report

We report the case of a 58‐year‐old female with severe postcapillary pulmonary hypertension (averaged mean pulmonary arterial pressure was 49 mmHg, pulmonary arterial wedge pressure 29 mmHg, and right atrial pressure 8 mmHg) due to heart failure with preserved ejection fraction. A left‐to‐right atrial shunt was created using an 8 mm cutting balloon, under transesophageal echocardiography guidance. Both pulmonary arterial and wedge pressure dramatically decreased after the procedure. Symptoms immediately improved and benefits were sustained at 6 months of follow‐up. This case suggests that iatrogenic septal defect using a cutting balloon could be an option to treat symptomatic postcapillary pulmonary hypertension.

Serum parathyroid hormone levels in patients with chronic right heart failure

Parathyroid hormone (PTH) is a novel cardiovascular biomarker which is particularly useful for detection and assessment of heart failure (HF). However, previous studies examining PTH in heart failure have primarily focused on left HF; thus, the relationship between PTH and right HF remains unclear. The aim of the present study was to evaluate the serum PTH levels in patients with chronic right HF. A total of 154 patients with chronic right HF were enrolled in the present study. A binary logistic regression analysis model was used to assess the independent predictive value of PTH levels in chronic right HF. Partial correlative analysis was used to demonstrate the relevance of PTH levels on the parameters of assessment of right heart function. A multiple linear regression analysis model was used to evaluate the independent factors of PTH levels in patients with right HF. The results showed that the serum PTH levels in the right HF group were significantly higher compared with the control group. After adjusting for predictors of right HF, serum PTH levels were associated with right HF with an odds ratio of 1.066 (95% confidence interval: 1.030-1.102, P<0.001. Serum PTH levels were independently correlated with plasma N-terminal pro-B-type natriuretic peptide levels, right ventricular end-diastolic diameter and severity of lower extremity edema (all P<0.05). Therefore, based on the results of the present study, PTH may be a useful biomarker for detection and assessment of right HF.

Tongsaimai reverses the hypertension and left ventricular remolding caused by abdominal aortic constriction in rats

Treating ventricular remodeling continues to be a clinical challenge. Studies have shown that hypertension is one of the most common causes of ventricular remodeling, and is a major cause of cardiovascular risk in adults. Here, we report that Tongsaimai (TSM), a Chinese traditional medicine, could inhibit arterial pressure and left ventricular pressure to improve hemodynamic abnormalities in rats impaired by abdominal aortic constriction (AAC). Administration of TSM significantly reduced the heart mass index and the left ventricular mass index significantly in AAC rats. TSM could also markedly ameliorate cardiac collagen deposition and reduce the concentration of hydroxyproline in the heart of AAC rats. Moreover, TSM alleviated cardiac histomorphology injury resulting from AAC, including reducing cardiomyocyte hypertrophy, fibrous connective tissue hyperplasia, cardiomyocyte apoptosis, replacement fibrosis and the disorders of myocardial myofibrils, intercalated discs, mitochondria and mitochondrial crista. In addition, the levels of transforming growth factor (TGF) - β and inflammation-related molecules including tumor necrosis factor-α (TNF-α), which were over-expressed with AAC, were decreased by STM. In conclusion, STM could reverse the hypertension and left ventricular remolding caused by abdominal aortic constriction in rats.

Efficacy and safety of tetramethylpyrazine phosphate on pulmonary hypertension: study protocol for a randomized controlled study

BACKGROUND

Tetramethylpyrazine (TMP), an active ingredient in the traditional Chinese herbal medicine Rhizoma Chuanxiong, has been used clinically for the prevention and treatment of cardiovascular disease. The benefits of TMP are largely attributed to its anti-oxidative and vasodilative properties. However, the efficacy of TMP in the treatment of pulmonary hypertension (PH) is unknown. We hypothesized that TMP may have a therapeutic effect in patients with PH.

METHODS/DESIGN

A randomized, single-blinded, clinical study with a TMP treatment group and a control group will be conducted to evaluate the efficacy and safety of TMP intervention in patients with PH. The recruitment target is 120 subjects meeting the following criteria: (i) at rest and at sea level, mean pulmonary artery pressure above 20 mmHg and pulmonary capillary wedge pressure below 15 mmHg; (ii) type 1 or 4 PH in the stable phase; (iii) age 15-70 years; (iv) 6-min walk distance between 100 and 450 m; (v) World Health Organization (WHO) functional classification of pulmonary hypertension of II, III, or IV. Subjects will be assigned randomly into two groups at a ratio of 1:2 (control:TMP). Both groups will receive routine treatment, and the treatment group will also receive oral TMP (100 mg) three times a day for 16 weeks. All patients will be followed up for 4, 8, 12, and 16 weeks; symptoms and patient compliance will be recorded.

DISCUSSION

We aimed to determine the efficacy and safety of TMP for the treatment of PH.

TRIAL REGISTRATION

Chinese Clinical Trial Register, ChiCTR1800018664. Registered on 2 October 2018.

Pulmonary hypertension in chronic heart failure: definitions, advances, and unanswered issues

Pulmonary hypertension (PH) is a common and severe complication of heart failure (HF). Consequently, HF is the leading cause of PH. For many years, specialists have attempted to better understand the pathophysiology of PH in HF, to define its prevalence and its impact on prognosis in order to improve the therapeutic management of these patients. Nowadays, despite the recent guidelines published on the subject, several points remain unclear or debated, and until now, no study has demonstrated the efficacy of any treatment. The aim of this review is to report the evolution of the concepts on post‐capillary PH (diagnosis, prevalence, prognosis, and therapeutics). The main issues are raised, focusing especially on the link between structural alterations and haemodynamic abnormalities, to discuss the possible reasons for treatment failures and future potential targets.