Stress pulmonary circulation parameters assessed by a cardiovascular magnetic resonance in patients after a heart transplant

Rest pulmonary circulation parameters such as pulmonary transit time (PTT), heart rate corrected PTT (PTTc) and pulmonary transit beats (PTB) can be evaluated using several methods, including the first-pass perfusion from cardiovascular magnetic resonance. As previously published, up to 58% of patients after HTx have diastolic dysfunction detectable only in stress conditions. By using adenosine stress perfusion images, stress analogues of the mentioned parameters can be assessed. By dividing stress to rest biomarkers, potential new ratio parameters (PTT ratio and PTTc ratio) can be obtained. The objectives were to (1) provide more evidence about stress pulmonary circulation biomarkers, (2) present stress to rest ratio parameters, and (3) assess these biomarkers in patients with presumed diastolic dysfunction after heart transplant (HTx) and in childhood cancer survivors (CCS) without any signs of diastolic dysfunction. In this retrospective study, 48 patients after HTx, divided into subgroups based on echocardiographic signs of diastolic dysfunction (41 without, 7 with) and 39 CCS were enrolled. PTT was defined as the difference between the onset time of the signal intensity increase in the left and the right ventricle. PTT in rest conditions were without significant differences when comparing the CCS and HTx subgroup without diastolic dysfunction (4.96 ± 0.93 s vs. 5.51 ± 1.14 s, p = 0.063) or with diastolic dysfunction (4.96 ± 0.93 s vs. 6.04 ± 1.13 s, p = 0.13). However, in stress conditions, both PTT and PTTc were significantly lower in the CCS group than in the HTx subgroups, (PTT: 3.76 ± 0.78 s vs. 4.82 ± 1.03 s, p < 0.001; 5.52 ± 1.56 s, p = 0.002). PTT ratio and PTTc ratio were below 1 in all groups. In conclusion, stress pulmonary circulation parameters obtained from CMR showed prolonged PTT and PTTc in HTx groups compared to CCS, which corresponds with the presumption of underlying diastolic dysfunction. The ratio parameters were less than 1.

Effect of immunosuppressive therapy in inflammatory cardiomyopathy: data from The Czech Inflammatory Cardiomyopathy Immunosuppressive Trial

INTRODUCTION

The indications for specific treatment in the cases of inflammatory cardiomyopathy are based on limited data from several small clinical trials.

AIM

A comparison of the effect of two dose regimens of combined immunosuppressive therapy by adding them to conventional heart failure therapy and comparing them with conventional heart failure therapy alone in patients with inflammatory cardiomyopathy.

METHODS AND STUDY POPULATION

We enrolled 20 patients; mean age 46.10±7.33 years, duration of symptoms <6 months, LVEF ≤40 %, NYHA class II-IV, with biopsy‑proven myocarditis. Patients were randomly separated into groups treated with immunosuppressive therapy in addition to conventional heart failure therapy or to a group treated with conventional heart failure therapy alone. Clinical and echocardiographic parameters were evaluated.

RESULTS

The baseline values of LVEF in the group of immunosuppressive therapy (LVEF 22.3±4.7 %) were similar to those in the group treated with conventional heart failure therapy (LVEF 21.7±4.7 %; p=0.757). After twelve months there was no statistically significant difference in LVEF between the two studied groups (LVEF 33.7±9.5 % for the immunosuppressive therapy group and 41.3±13.0 % for the conventional therapy group; p=0.175).

CONCLUSION

In our study population, we proved no positive effect of combined immunosuppressive therapy on the left ventricular function over 12 months. The main limitation of the study is the small number of enrolled patients (Tab. 4, Fig. 1, Ref. 35).

Pulmonary circulation biomarkers acquired by cardiovascular magnetic resonance in population after heart transplant

Funding Acknowledgements

Type of funding sources: Public grant(s) – EU funding. Main funding source(s): This study was supported by the European Regional Development Fund - Project ENOCH. This study was conducted at Masaryk University as part of the project "New Methods in Diagnostic and Stratification of Cardiovascular Diseases" MUNI/A/1393/2019 with the support of the Specific University Research Grant, as provided by the Ministry of Education, Youth and Sports of the Czech Republic in 2019.

Introduction 

Right heart catheterization still remains the golden standard in measuring pulmonary circulation parameters, although its clinical use is limited due to it being an invasive examination. Pulmonary circulation biomarkers acquired by cardiovascular magnetic resonance (CMR) could provide a non-invasive alternative for assuming congestion in patients. Biomarkers such as pulmonary transit time (PTT), pulmonary transit beats (PTB) and pulmonary blood volume index (PBVI) are not new themselves, however, data on cut-off values of these biomarkers and on different populations are limited. To our knowledge, these biomarkers have never been measured in patients after heart transplant (HT) before and PTT from stress perfusion has only been acquired by a single study, which makes the data on this relatively new marker very limited. 

Purpose 

The purpose of this study was to calculate PTT stress/rest ratio and provide more evidence about pulmonary circulation biomarkers in HT patients. 

Methods 

In this retrospective study, 38 patients after HT who had undergone a CMR examination including contrast methods and stress CMR perfusion were enrolled. PTT values in both rest and stress perfusion were measured as peak-to-peak time in main contrast bolus of dual-bolus stress CMR examination. PTB was calculated by dividing PTT by RR interval obtained from heart rate and PBVI from PTB and right ventricle systolic volume. PTT under stress and rest condition was afterwards compared and PTT ratio was calculated dividing stress values by rest values. Obtained results were further compared to a healthy group as published previously. PTT ratio of HT patients was then compared to measurements conducted on a control group consisting of 10 patients after anthracycline treatment. 

Results 

Patients after HT showed biomarker values as follows

PBVI 250 ± 59 mL/m2, PTT 6,26 ± 1,05 s, PTT stress 5,66 ± 1,09 s, PTB 7,39 ± 1,31 and PTT ratio 0,91 ± 0,14. These results resemble previously published healthy group values (PBVI 308 ± 92 ml/m2, PTT 6,8 s, PTB 7) and none of the patients enrolled in our study crossed the presented cut-off value of PBVI 492 mL/m2 for hemodynamic congestion. PTT ratio in our control group was 0,77 ± 0,14. In both the populations, PTT values under stress were lower than in rest condition and therefore PTT ratio values were below 1.

Conclusions

The study provided more evidence about pulmonary circulation biomarkers acquired by CMR in HT patients and presented PTT ratio as a new biomarker. Patients 1 year after HT have comparable values to those of healthy population. PTT stress values were shorter than PTT rest values in both HT group and control group.

The role of inflammation in recent-onset dilated cardiomyopathy

Background

The aetiology of recent-onset dilated cardiomyopathy (RODCM) includes inflammatory, genetic, toxic and metabolic causes. Delineating the role of inflammation on the genetic background could improve risk stratification.

Purpose

We aimed to ascertain the role of inflammation evaluated by serum CRP immunohistochemical and PCR analysis of endomyocardial biopsy (EMB) in conjunction with genetic testing in left ventricular reverse remodelling (LVRR) in 12-month follow-up.

Methods

83 RODCM patients enrolled in this prospective observational study underwent 12-month echocardiographic follow up whole-exome sequencing, and EMB. Presence of cardiotropic viruses was determined by PCR analysis of the EMB samples. Inflammation was defined according to TIMIC immunohistochemical criteria as the presence of &gt;7 CD3+ lymphocytes/mm2 and/or &gt;14 infiltrating leukocytes (LCA+ cells/mm2). LVRR was defined as an absolute increase in LV ejection fraction &gt; +10% and a relative decrease of LV end-diastolic diameter &gt;−10% at 12 months.

Results

LVRR occurred in 28 (34%) of all cases. PCR analysis uncovered cardiotropic viruses in 55 (66%) patients, with highest prevalence of parvovirus B19 (47%). (Figure 1) EMB analysis detected inflammation in 28 (34%) cases and inflammation significantly positively predicted LVRR (P=0.019). Sequencing identified disease-related gene variants (ACMG class 3–5) in 45 (54%) patients. Carriers of non-titin gene variants showed a lowest probability of 12-month LVRR (19%) P=0.041. Combination of genetic findings and inflammation did not improve the prediction of LVRR in 12 months. (Table 1)

Conclusion

Both myocardial inflammation and disease-causing variants can be identified in a large proportion of RODCM cases. Prognostic value of CRP and virus detection is low. Non-titin disease-related variants carriers of are less likely to reach LVRR. In contrast, myocardial inflammation detected by EMB predicts favourable remodelling in 12 months.

Figure 1

Funding Acknowledgement

Type of funding source: None

Identification of a Diagnostic Set of Endomyocardial Biopsy microRNAs for Acute Cellular Rejection Diagnostics in Patients after Heart Transplantation Using Next-Generation Sequencing

Introduction: Acute cellular rejection (ACR) of heart allografts represents the most common reason for graft failure. Endomyocardial biopsies (EMB) are still subject to substantial interobserver variability. Novel biomarkers enabling precise ACR diagnostics may decrease interobserver variability. We aimed to identify a specific subset of microRNAs reflecting the presence of ACR. Patients and Methods: Monocentric retrospective study. A total of 38 patients with the anamnesis of ACR were identified and for each patient three consecutive samples of EMB (with, prior and after ACR) were collected. Sixteen trios were used for next-generation sequencing (exploratory cohort); the resting 22 trios were used for validation with qRT-PCR (validation cohort). Statistical analysis was performed using R software. Results: The analysis of the exploration cohort provided the total of 11 miRNAs that were altered during ACR, the three of which (miR-144, miR-589 and miR-182) were further validated in the validation cohort. Using the levels of all 11 miRNAs and principal component analysis, an ACR score was created with the specificity of 91% and sensitivity of 68% for detecting the presence of ACR in the EMB sample. Conclusion: We identified a set of microRNAs altered in endomyocardial biopsies during ACR and using their relative levels we created a diagnostic score that can be used for ACR diagnosis.

P1815The impact of PVB19 presence in myocardium in recent onset dilated cardiomyopathy

Introduction

The most common virus in myocardium of patients with recent onset dilated cardiomyopathy (RODCM) is PVB19. Opinions on its pathogenicity are different. According to some, viral load has to be evaluated and if it is low, the PVB19 has no potential to induce inflammation. Others recommend assessment of viral replication, while “innocent” are those cases where replication activity is low.

Purpose

To compare the development of echocardiographic parameters in patients with RODCM with isolated presence of PVB19 in low viral load (below 500 copies per μg nucleic acid) against a group in which no virus was detected in the myocardium.

Patient and methods

243 patients with RODCM, in 151 cases (62%), the virus was detected in the myocardium (PCR+ group), in 92 cases the finding was negative (PCR−; ie 38%). In the PCR+ group, PVB19 was captured in 135 cases (89% of all PCR+), in 121 cases of them was PVB19 the only one isolated virus (PCRPVB19+; 80% of all PCR+). The viral presence was assessed by real time PCR.

Results

In the PCR− group, the left ventricular ejection fraction (LVEF) was 23.5±7.2%, in the PCRPVB19+ group 24.6±7.1% (p=0.26). Left ventricle end-diastolic diameter (LVEDD) in PCR− was 66.4±8.9mm vs 65.5±7.9mm in PCRPVB19+ (p=0.42), right ventricle diameter (RV) 33.1±5.7mm vs. 33.4±5.2mm (p=0.69), TAPSE 19.5±4.1mm vs 18.9±4.0mm (p=0.28) and E/é 14.0±5.7 vs. 14.9±7.0 (p=0.32). In the 12-month control, LVEF in the PCR− was 35.5±12.3% (p<0.001 for comparison with baseline), in PCRPVB19+ 35.3±12.3% (p<0.001 for comparison with baseline; p=0.92 for difference between groups); LVEDD in PCR− was 62.0±9.3mm vs 62.1±9.3mm in PCRPVB19+ (both p<0.001 for comparison with baseline, p=0.91 for difference between groups), RV 31.6±5.5mm vs. 31.6±5.4mm (p=0.033, resp. p=0.003 for comparison with baseline; p=0.98 for difference between groups), TAPSE 20.7±4.3mm vs. 20.7±4.4mm (p=0.026, resp. p<0.001 for comparison with baseline; p=0.98 for difference between groups), and E/e' 10.3±4.1 vs. 10.4±4.1 (both p<0.001 for comparison with baseline; p=0.93 for difference between groups).

Conclusion

PVB19 presence in myocardium had no effect on the development of echocardiographic parameters in RODCM patients in one-year follow-up.

Acknowledgement/Funding

Supported by Ministry of Health of Czech Republic AZV Grant 16-30537A

[Farmacotherapy of hypertension after heart transplantation]

Heart transplantation is now used for the treatment of severe heart failure. In a long-term patient follow-up, hypertension has been identified as a complication. Incidence of hypertension in patients treated with cyclosporine and prednisone is between 70-90%. Besides the traditional mechanisms (renin-angiotensin system, fluid volume and peripheral resistance), aetiology of hypertension includes negative effect of cardiac denervation, cyclosporine immunosuppression, administration of corticosteroids and nephropathy. There is no night drop in the blood pressure and heart rate. Treatment aims to maintain cyclosporine level as low as possible and, if feasible, to discontinue steroids during the first year. Hypertension is usually treated with a combination therapy. Our own observations suggest that the majority of post-transplantation patients have a dual therapy. Calcium channel blockers should be the treatment of choice as they also have an effect on graft vasculopathy. Angiotenzin-converting enzyme (ACE) inhibitors or angiotensin II receptor blockers (ARB), beta-blockers and diuretics are also recommended. Long-acting products should be preferred.