Risk scores' performance and their impact on operative decision-making in left-sided endocarditis: a cohort study

The accuracy of contemporary risk scores in predicting perioperative mortality in infective endocarditis (IE) remains controversial. The aim is to evaluate the performance of existent mortality risk scores for cardiovascular surgery in IE and the impact on operability at high-risk thresholds. A single-center retrospective review of adult patients diagnosed with acute left-sided IE undergoing surgery from May 2014 to August 2019 (n = 142) was done. Individualized risk calculation was obtained according to the available mortality risk scores: EuroScore I and II, PALSUSE, Risk-E, Costa, De Feo-Cotrufo, AEPEI, STS-risk, STS-IE, APORTEI, and ICE-PCS scores. A cross-validation analysis was performed on the score with the best area under the curve (AUC). The 30-day survival was 96.5% (95%CI 91-98%). The score with worse area under the curve (AUC = 0.6) was the STS-IE score, while the higher was for the RISK-E score (AUC = 0.89). The AUC of the majority of risk scores suggested acceptable performance; however, statistically significant differences in expected versus observed mortalities were common. The cross-validation analysis showed that a large number of survivors (> 75%) would not have been operated if arbitrary high-risk threshold estimates had been used to deny surgery. The observed mortality in our cohort is significantly lower than is predicted by contemporary risk scores. Despite the reasonable numeric performance of the analyzed scores, their utility in judging the operability of a given patient remains questionable, as demonstrated in the cross-validation analysis. Future guidelines may advise that denial of surgery should only follow a highly experienced Endocarditis Team evaluation.

Predictive factors for requiring heart transplantation in patients with hypertrophic cardiomyopathy: data from a referral center

Background

Heart transplant (HT) remains the last treatment option for patients with non-obstructive hypertrophic cardiomyopathy (HCM) who develop end-stage heart failure (HF). Early identification of patients who may require a HT in the future is crucial in order to advise them, establish the appropriate follow-up and determine the appropriate time to include them in the waiting list.

Objectives

Our study sought to find predictive factors related with requiring HT during follow-up in patients with HCM.

Methods

Consecutive patients with HCM referred to a HCM monographic clinic from 2018 to 2020 (HCM controls) and transplanted patients due to HCM in the same tertiary HT hospital since 2003 (cases) were included. Baseline (on the date of HCM diagnosis) and longitudinal data regarding clinical, genetic, ECG and echocardiographic variables were retrospectively evaluated. Follow-up was registered from HCM diagnosis to HT (in cases) or last medical check up (controls).

Results

A total of 157 patients (24 HCM-HT cases and 133 HCM controls) were included (45±19 yo; 57% male). At the time of MCH diagnosis (Table), cases were significantly younger than controls, were more frequently symptomatic and showed significantly higher BNP levels and more advanced diastolic dysfunction (larger left atrium, higher E/A ratio and lower e'); also, HCM-HT reported more family history and had higher proportion of pathogenic mutations (being MYH7 the most frequently involved). Left ventricular (LV) systolic function was slightly reduced in HCM-HT cases. In contrast, HCM controls were more frequently diagnosed by casual findings or family screening and had more LV outflow tract obstruction at first medical evaluation. LV maximal wall thickness (MWT) did not differ between groups. During a median follow-up since HCM diagnosis of 6.2 years (median follow-up of 8.9 and 7.1 years in cases and controls, respectively), HCM-HT cases presented a higher incidence of sustained ventricular tachycardia or ICD therapy (HR=4.0; CI95%:1.6–10.0 p=0.03) and HF admissions (HR=3.9; CI95%:1.8–8.1 p<0.001). There were no cardiovascular deaths during follow-up.

Conclusions

The presence of symptoms in a young non-obstructive HCM patient, along with family history and a pathogenic mutation, should advice clinicians a closer follow-up and early transfer to a HT referral center, especially if associated with diastolic dysfunction and high BNP values.

Funding Acknowledgement

Type of funding sources: None. Table 1

Aetiology-discriminative multimodality imaging of hypertrophic cardiomyopathy: deformation patterns relate to synchrotron-based assessment of microstructural tissue remodelling

Funding Acknowledgements

Type of funding sources: Public grant(s) – EU funding. Main funding source(s): Horizon 2020 European Commission Project H2020-MSCA-ITN-2016 (764738) and the Clinical Research in Cardiology grant from the Spanish Cardiac Society.

Background

The aetiology of left ventricular hypertrophy (LVH) is a relevant clinical challenge with consequences for patient management. Phenotypes resulting from hypertensive remodelling and sarcomere mutation often overlap. Synchrotron X-ray phase-contrast imaging (X-PCI) is a technique that can provide 3-dimensional detailed information on myocardial micro-structure non-destructively. The aim is to relate macrostructural/functional, non-invasive, imaging phenotypes of hypertrophic cardiomyopathy (HCM) to the underlying myocardial microstructure assessed with X-PCI.

Methods

Myocardial tissue samples were obtained from three patients (P1-3) with obstructive myocardial hypertrophy undergoing septal myectomy. Medical history and the 5-year HCM risk scores were evaluated. The patients were imaged with magnetic resonance imaging and echocardiography prior to procedure. Myocardial structure was assessed with wall thickness, late gadolinium enhancement (LGE), whereas function with speckle-tracking deformation (STE) and tissue Doppler imaging (TDI). Myectomy tissue was imaged with X-PCI in the TOMCAT beamline, using a multiscale propagation-based protocol combining a low-resolution (LR) and a high-resolution (HR) setup (5.8 and 0.7 um pixel size, respectively).

Results

The clinical and imaging data are shown in Fig 1. On initial assessment, wall thickness, LGE distribution, global longitudinal strain and septal TDI demonstrated a similar macrostructural and functional phenotype of P1 and P2, whereas P3 stood out with more severe hypertrophy, scarring and dysfunction. Additional regional deformation analysis with STE revealed reduced deformation in the basal and mid septum in P1, paired with a hypertensive pattern of post-systolic shortening (PSS) (yellow arrows). In comparison, in P2 and P3, deformation was more heterogeneous regionally, with regions of almost complete absence of deformation (orange arrows). Upon further exploration with TDI, areas with abnormal deformation were identified on the transition from basal to mid septum in both P2 and P3, whereas deformation was normal, but reduced in P1, and paired with PSS. LR X-PCI defined regions of interest to scan with HR (yellow frame), where HR revealed extensive interstitial fibrosis (orange arrow) with normal myocyte size and organisation in P1, compatible with severe hypertensive remodelling. However, in P2 and P3, patches of fibrosis (yellow arrow) paired with enlarged myocytes organized in visible disarray, considerably more prominent in P3, were both compatible with sarcomere-mutation HCM.

Conclusion

The results demonstrate multiscale phenotyping of HCM - relating micro- and macrostructural findings to function, and integrating multimodality data. In-depth regional deformation analysis, validated by synchrotron-based microstructural analysis, showed potential to identify distinct imaging phenotypes in HCM, distinguishing between overlapping presentations in different aetiologies.

Abstract Figure 1

474 Isolated pulmonary endocarditis

INTRODUCTION

Isolated pulmonary endocarditis is a rare entity, especially in patients without predisposing factors, being its current incidence less than 1% of the total cases of infectious endocarditis. This is due to the lower right heart pressures and a decrease of intravenous drug-consum, being most of the cases nowadays, related to congenital right-heart diseases or pacemakers and defibrillators implants.

CLINICAL CASE

A 35 year-old man, tobacco smoker and intravenous cocaine consumer since he was 25, was admitted to our Emergency Department for fever up to 40ºC, cough and dyspnea started three days before admission. In the anamnesis he refereed intravenous consum of cocaine and sharing of syringes the last week. On physical examination he was tachycardic and signs of heart right failure were present such as jugular ingurgitation and peripheral edema. No murmurs were heard. No respiratory failure was detected at any time. Blood test analysis showed high levels of protein C reactive and leukocytosis. Blood cultures were positive for S. aureus (OXA-S) in the first 24h. Chest X-ray (image 1) showed a necrotizing bilateral pneumonia that was confirmed with the presence of cavitated images in the pulmonary CT (image 2). Antibiotic treatment was started with daptomicine + cloxaciline. With the suspicion of right endocarditis a transthoracic echocardiography was performed, showing the presence of a big vegetation (4x1cm) on the pulmonary valve that caused moderate pulmonary insufficiency (images 3, 4). Neither tricuspid nor left side valves were involved. Biventricular function was conserved and hyperdynamic. Endocarditis diagnosis was definitive and due to the presence of multiple right embolisms and the big size of the vegetation, the patient underwent cardiac surgery. Intra-surgical finding demonstrated a big vegetation of almost 5 cm (image 5) depending of the posterior pulmonary valve that was removed; the posterior valve needed to be repaired. Posterior clinical evolution was correct without complications, completing 17 days of i.v. antibiotics (cloxaciline) before discharge.

CONCLUSIONS

Right endocarditis is a rapidly progressive disease due to the fact that staphylococcus are the most frequent microorganisms involved. Valvular destruction and secondary embolic phenomena are the rule. Tricuspid valve is involved most of the times being the isolated pulmonary valve affection very uncommon.

Abstract 474 Figure. CT, Echo and surgical images

P4684Differential right ventricular adaptation patterns to chronic pressure overload

Background

Right ventricular (RV) dysfunction is the most important prognostic factor in chronic pulmonary hypertension (PH), but its underlying mechanisms are unknown. Clinical observation and prior experimental work suggest that RV pressure overload is not the only cause since the degree of RV adaptation varies with similar RV end-systolic pressures.

Purpose

Our aim was to characterize serial RV adaptation by cardiac magnetic resonance (CMR) in 3 different experimental large-animal models of increased afterload: a model of chronic postcapillary PH, a model of PH secondary to systemic-to-pulmonary shunt and a model of mechanical RV pressure overload (generated by pulmonary artery [PA] banding).

Methods

Four-week old piglets underwent pulmonary vein banding surgery to generate the chronic postcapillary PH model (n=20), aorto-pulmonary shunt (n=6), PA banding (n=7) or sham operation (n=7). They were followed up monthly with CMR and right heart catheterization (RHC). All procedures followed the “Principles of laboratory animal care”. Comparison of continuous variables among groups was performed with Mann-Whitney U test.

Results

Animals with either postcapillary PH or PH secondary to aorto-pulmonary shunt presented significant RV dilatation, hypertrophy and dysfunction that was maintained during follow-up (median RV end-systolic volume [RVESV]=32.6 ml/m2 for postcapillary PH and 32.6 ml/m2 for shunt vs. 16.1 ml/m2 in sham controls; median RV ejection fraction [RVEF]=61.5% for postcapillary PH and 60.5% for shunt vs. 69.6% in sham controls at the end of follow-up). Animals with PA banding also presented with significant RV dilatation and hypertrophy at the first month follow-up, but unlike all other groups, they developed reverse RV remodeling from the second month onwards and maintained normal RV volumes and RVEF values until the end of follow-up despite having severe RV hypertrophy (RV mass 22.6 g/m2 in PA banding vs. 16.1 g/m2 in controls at the 4th month follow-up; Figure).

CMR parameters (median values).

Conclusion

In PH there is a maladaptive RV hypertrophy that is not present in a model of progressive RV pressure overload without alterations of the pulmonary circulation. Increased RV pressure overload alone does not fully explain PH-associated RV dysfunction. Further research is needed to clarify the underlying mechanisms of adaptive and maladaptive hypertrophy in PH.

Acknowledgement/Funding

The CNIC is supported by the Ministerio de Ciencia, Innovaciόn y Universidades and the Pro CNIC Foundation, and is a Severo Ochoa Center of Excellence

P596Early markers of right ventricular involvement in experimental chronic postcapillary pulmonary hypertension

Background

In chronic pulmonary hypertension (PH), the main cause of death is right ventricular (RV) failure. However, the onset of RV dysfunction varies significantly among patients. Early recognition of RV maladaptation would be highly relevant.

Purpose

To identify cardiac magnetic resonance (CMR)-derived parameters affected in early stages of PH before the development of RV dysfunction.

Methods

Experimental chronic PH was generated by pulmonary vein banding in 76 pigs whereas 14 animals underwent sham operation. Animals were followed-up monthly with right heart catheterization (RHC) and immediate CMR for a maximum of 9 months. CMR exams included a T1-mapping sequence to quantify equilibrium-extracellular volume (ECV) at the RV insertion points. Pairs of RHC and CMR examinations were compared among controls and PH with normal RV ejection fraction (RVEF≥55%) or reduced (REVF<55%) using ANCOVA test with Bonferroni correction. All procedures followed the “Principles of laboratory animal care”.

Results

In the presence of PH confirmed by RHC and normal RVEF, the RV displays significant hypertrophy and increased myocardial native T1 and ECV, despite preserved ventricular dimensions and PA flow (Fig 1B). In advanced stages of the disease, RV-AP uncoupling and reduced PA pulsatility develop together with RV dilatation and failure (Fig 1C).

CMR parameters in sham and PH animals Sham controls (n=25 evaluations) PH with normal RVEF (n=155 evaluations) PH with low RVEF (n=70) RVEF (%) 62±5 61±4 47±8# RVEDV (mL/m2) 73±18 83±17 111±29# RVESV (mL/m2) 28±8 32±8 61±25# RV mass (g/m2) 17±4 23±5* 30±11# PA area (cm2/m2) 5.5±1.2 6.3±1.6 8.7±2.2# Native T1 anterior RVIP (ms) 983±75 1043±78* 1055±90# ECV anterior RVIP (%) 27±5 31±6* 36±7# Native T1 inferior RVIP (ms) 959±68 1022±71* 1032±99# ECV inferior RVIP (%) 25±5 31±6* 36±7# PA pulsatility (%) 29±6 27±7 21±3# Ea/Emax 40±16 47±11 97±65# RVEDV: RV end-diastolic volume; RVESV: RV end-systolic volume; RVIP: RV insertion point. *p<0.05 1 vs. 2; #1 vs. 3.

NativeT1: control, PH-normal RV, RV dysf

Conclusion

RV hypertrophy and ECV expansion are early mechanisms in RV adaptation to postcapillary PH, whereas ventricular and PA dilatation, RV-PA uncoupling and reduced pulsatility appear in more advanced stages concurring with systolic dysfunction.

Acknowledgement/Funding

The CNIC is supported by the Ministerio de Ciencia, Innovaciόn y Universidades and the Pro CNIC Foundation, and is a Severo Ochoa Center of Excellence