Reappraisal of the Concept and Implications of Pulmonary Hypertension in Degenerative Mitral Regurgitation.

BACKGROUND: European and U.S. clinical guidelines diverge regarding pulmonary hypertension (PHTN) in degenerative mitral regurgitation (DMR). Gaps in knowledge underpinning these divergences affect risk assessment and management recommendations attached to systolic pulmonary pressure (SPAP) in DMR. OBJECTIVES: This study sought to define PHTN links to DMR severity, prognostic thresholds, and independent outcome impact in a large quantitative DMR registry. METHODS: This study gathered a large multicentric registry of consecutive patients with isolated moderate-to-severe DMR, with DMR and SPAP quantified prospectively at diagnosis. RESULTS: In 3,712 patients (67 ± 15 years, 36% women) with ≥ moderate-to-severe DMR, effective regurgitant orifice (ERO) was 0.42 ± 0.19 cm2, regurgitant volume 66 ± 327 mL/beat and SPAP 41 ± 16 mm Hg. Spline-curve analysis showed excess mortality under medical management emerging around SPAP 35 mm Hg and doubling around SPAP 50 mm Hg. Accordingly, severe pulmonary hypertension (sPHTN) (SPAP ≥50 mm Hg) was detected in 916 patients, moderate pulmonary hypertension (mPHTN) (SPAP 35-49 mm Hg) in 1,128, and no-PHTN (SPAP <35 mm Hg) in 1,668. Whereas SPAP was strongly associated with DMR-ERO, nevertheless excess mortality with sPHTN (adjusted HR: 1.65; 95% CI: 1.24-2.20) and mPHTN (adjusted HR: 1.44; 95% CI: 1.11-1.85; both P ≤ 0.005) was observed independently of ERO and all baseline characteristics and in all patient subsets. Nested models demonstrated incremental prognostic value of mPHTN and sPHTN (all P < 0.0001). Despite higher operative risk with mPHTN and sPHTN, DMR surgical correction was followed by higher survival in all PHTN ranges with strong survival benefit of early surgery (<3 months). Postoperatively, excess mortality was abolished (P ≥ 0.30) in mPHTN, but only abated in sPHTN. CONCLUSIONS: This large international registry, with prospectively quantified DMR and SPAP, demonstrates a Doppler-defined PHTN impact on mortality, independent of DMR severity. Crucially, it defines objectively the new and frequent mPHTN range, independently linked to excess mortality under medical management, which is abolished by DMR correction. Thus, at DMR diagnosis, Doppler-SPAP measurement defining these new PHTN ranges, is crucial to guiding DMR management.

Hemodynamic implications of mitral annular calcification in patients undergoing transcatheter aortic valve implantation for severe aortic stenosis.

PURPOSES: Predicting hemodynamic changes of stenotic mitral valve (MV) lesions with mitral annular calcification (MAC) following transcatheter aortic valve implantation (TAVI) may inform clinical decision-making. This study aimed to investigate the association between the MAC severity quantified by computed tomography (CT) and changes in mean transmitral gradient (mTMG), mitral valve area (MVA) and stroke volume index (SVi) following TAVI. METHODS AND RESULTS: A total of 708 patients (median age 81, 52% male) with severe aortic stenosis (AS) underwent pre-procedural CT and pre- and post-TAVI transthoracic echocardiography. According to the classification of MAC severity determined by CT, 299 (42.2%) patients had no MAC, 229 (32.3%) mild MAC, 102 (14.4%) moderate MAC, and 78 (11.0%) severe MAC. After adjusting for age and sex, there was no significant change in mTMG following TAVI (Δ mTMG = 0.07 mmHg, 95% CI -0.10 to 0.23, P = 0.92) for patients with no MAC. In contrast, patients with mild MAC (Δ mTMG = 0.21 mmHg, 95% CI 0.01 to 0.40, P = 0.018), moderate MAC (Δ mTMG = 0.31 mmHg, 95% CI 0.02 to 0.60, P = 0.019) and severe MAC (Δ mTMG = 0.43 mmHg, 95% CI 0.10 to 0.76, P = 0.0012) had significant increases in mTMG following TAVI, with greater changes associated with increasing MAC severity. In contrast, there was no significant change in MVA or SVi following TAVI. CONCLUSION: In patients with severe AS undergoing TAVI, MAC severity was associated with greater increases in post-procedural mTMG whereas MVA or SVi remained unchanged. MAC severity should be considered for potential subsequent MV interventions if TAVI does not improve symptoms.

Factors influencing post-surgical survival in degenerative mitral regurgitation.

AIMS: Indications for surgery in patients with degenerative mitral regurgitation (DMR) are increasingly liberal in all clinical guidelines but the role of secondary outcome determinants (left atrial volume index ≥60 mL/m2, atrial fibrillation, pulmonary artery systolic pressure ≥50 mmHg and moderate to severe tricuspid regurgitation) and their impact on post-operative outcome remain disputed. Whether these secondary outcome markers are just reflective of the DMR severity or intrinsically affect survival after DMR surgery is uncertain and may have critical importance in the management of patients with DMR. To address these gaps of knowledge the present study gathered a large cohort of patients with quantified DMR, accounted for the number of secondary outcome markers and examined their independent impact on survival after surgical correction of the DMR. METHODS AND RESULTS: The Mitral Regurgitation International DAtabase-Quantitative registry includes patients with isolated DMR from centres across North America, Europe, and the Middle East. Patient enrolment extended from January 2003 to January 2020. All patients undergoing mitral valve surgery within 1 year of registry enrolment were selected. A total of 2276 patients [65 (55-73) years, 32% male] across five centres met study eligibility criteria. Over a median follow-up of 5.6 (3.6 to 8.7) years, 278 patients (12.2%) died. In a comprehensive multivariable Cox regression model adjusted for age, EuroSCORE II, symptoms, left ventricular ejection fraction (LVEF), left ventricular end-systolic diameter (LV ESD) and DMR severity, the number of secondary outcome determinants was independently associated with post-operative all-cause mortality, with adjusted hazard ratios of 1.56 [95% confidence interval (CI): 1.11-2.20, P = 0.011], 1.78 (95% CI: 1.23-2.58, P = 0.002) and 2.58 (95% CI: 1.73-3.83, P < 0.0001) for patients with one, two, and three or four secondary outcome determinants, respectively. A model incorporating the number of secondary outcome determinants demonstrated a higher C-index and was significantly more concordant with post-operative mortality than models incorporating traditional Class I indications alone [the presence of symptoms (P = 0.0003), or LVEF ≤60% (P = 0.006), or LV ESD ≥40 mm (P = 0.014)], while there was no significant difference in concordance observed compared with a model that incorporated the number of Class I indications for surgery combined (P = 0.71). CONCLUSION: In this large cohort of patients treated surgically for DMR, the presence and number of secondary outcome determinants was independently associated with post-surgical survival and demonstrated better outcome discrimination than traditional Class I indications for surgery. Randomised controlled trials are needed to determine if patients with severe DMR who demonstrate a cardiac phenotype with an increasing number of secondary outcome determinants would benefit from earlier surgery.

Approach to optimal assessment of right ventricular remodelling in heart transplant recipients: insights from myocardial work index, T1 mapping, and endomyocardial biopsy.

AIMS: Right ventricular (RV) dysfunction is an important cause of graft failure after heart transplantation (HTx). We sought to investigate relative merits of echocardiographic tools and cardiac magnetic resonance (CMR) with T1 mapping for the assessment of functional adaptation and remodelling of the RV in HTx recipients. METHODS AND RESULTS: Sixty-one complete data set of echocardiography, CMR, right heart catheterization, and biopsy were obtained. Myocardial work index (MWI) was quantified by integrating longitudinal strain (LS) with invasively measured pulmonary artery pressure. CMR derived RV volumes, T1 time, and extracellular volume (ECV) were quantified. Endomyocardial biopsy findings were used as the reference standard for myocardial microstructural changes. In HTx recipients who never had a previous allograft rejection, longitudinal function parameters were lower than healthy organ donors, while ejection fraction (EF) (52.0 ± 8.7%) and MWI (403.2 ± 77.2 mmHg%) were preserved. Rejection was characterized by significantly reduced LS, MWI, longer T1 time, and increased ECV that improved after recovery, whereas RV volumes and EF did not change MWI was the strongest determinant of rejection related myocardial damage (area under curve: 0.812, P < 0.0001, 95% CI: 0.69-0.94) with good specificity (77%), albeit modest sensitivity. In contrast, T1 time and ECV were sensitive (84%, both) but not specific to detect subclinical RV damage. CONCLUSION: Subclinical adaptive RV remodelling is characterized by preserved RV EF despite longitudinal function abnormalities, except for MWI. While ultrastructural damage is reflected by MWI, ECV, and T1 time, only MWI has the capability to discriminate functional adaptation from transition to subclinical structural damage.

Incorporating coronary artery calcium scoring in the prediction of obstructive coronary artery disease with myocardial ischemia: a study with sequential use of coronary computed tomography angiography and positron emission tomography imaging.

BACKGROUND: Additional strategies are needed to refine the referral for diagnostic testing of symptomatic patients with suspected coronary artery disease (CAD). We aimed to compare various models to predict hemodynamically obstructive CAD. METHODS AND RESULTS: Symptomatic patients with suspected CAD who underwent coronary artery calcium scoring (CACS) and sequential coronary computed tomography angiography (CCTA) and [15O]H2O positron emission tomography (PET) myocardial perfusion imaging were analyzed. Obstructive CAD was defined as a suspected coronary artery stenosis on CCTA with myocardial ischemia on PET (absolute stress myocardial perfusion ≤ 2.4 mL/g/min in ≥ 1 segment). Three models were developed to predict obstructive CAD-induced myocardial ischemia using logistic regression analysis: (1) basic model: including age, sex and cardiac symptoms, (2) risk factor model: adding number of risk factors to the basic model, and (3) CACS model: adding CACS to the risk factor model. Model performance was evaluated using discriminatory ability with area under the receiver-operating characteristic curves (AUC). A total of 647 patients (mean age 62 ± 9 years, 45% men) underwent CACS and sequential CCTA and PET myocardial perfusion imaging. Obstructive CAD with myocardial ischemia on PET was present in 151 (23%) patients. CACS was independently associated with myocardial ischemia (P < .001). AUC for the discrimination of ischemia for the CACS model was superior over the basic model and risk factor model (P < .001). CONCLUSIONS: Adding CACS to the model including age, sex, cardiac symptoms and number of risk factors increases the accuracy to predict obstructive CAD with myocardial ischemia on PET in symptomatic patients with suspected CAD.

Comparative analysis of right ventricular strain in Fabry cardiomyopathy and sarcomeric hypertrophic cardiomyopathy.

AIMS: To perform a comparative analysis of right ventricle (RV) myocardial mechanics, assessed by 2D speckle-tracking echocardiography (2D-STE), between patients with Fabry disease and patients with sarcomeric disease. METHODS AND RESULTS: Patients with Fabry cardiomyopathy (FC) (n = 28) were compared with patients with sarcomeric hypertrophic cardiomyopathy (HCM), matched for degree of left ventricle hypertrophy (LVH) and demographic characteristics (n = 112). In addition, patients with Fabry disease and no LVH [phenotype-negative carriers of pathogenic α-galactosidase gene mutations (GLA LVH-)] (n = 28) were compared with age and sex-matched carriers of sarcomeric gene mutations without LVH [Phenotype-negative carriers of pathogenic sarcomeric gene mutations (Sarc LVH-)] (n = 56). Standard echocardiography and 2D-STE were performed in all participants. Despite a subtle impairment of RV global longitudinal strain (RV-GLS) was common in both groups, patients with FC showed a more prominent reduction of RV free wall longitudinal strain (RV-FWS) and lower values of difference between RV-FWS and RV-GLS (ΔRV strain), in comparison to individuals with HCM (P < 0.001 and P = 0.002, respectively). RV-FWS and ΔRV strain demonstrated an independent and additive value in discriminating FC from HCM, over the presence of symmetric LVH, systolic anterior motion of the mitral valve and RV hypertrophy. Similar results were found in GLA LVH- patients: they had worse RV-FWS and lower values of ΔRV strain as compared to Sarc LVH- patients (both P < 0.001). CONCLUSION: Patients with FC show a specific pattern of RV myocardial mechanics, characterized by a larger impairment of RV-FWS and lower ΔRV strain in comparison to patients with HCM, which may be helpful in the differential diagnosis between these two diseases.

Prevalence and Prognostic Implications of Discordant Grading and Flow-Gradient Patterns in Moderate Aortic Stenosis.

BACKGROUND: The prognostic implications of discordant grading in severe aortic stenosis (AS) are well known. However, the prevalence of different flow-gradient patterns and their prognostic implications in moderate AS are unknown. OBJECTIVES: The purpose of this study was to investigate the occurrence and prognostic implications of different flow-gradient patterns in patients with moderate AS. METHODS: Patients with moderate AS (aortic valve area >1.0 and ≤1.5 cm2) were identified and divided in 4 groups based on transvalvular mean gradient (MG), stroke volume index (SVi), and left ventricular ejection fraction (LVEF): concordant moderate AS (MG ≥20 mm Hg) and discordant moderate AS including 3 subgroups: normal-flow, low-gradient moderate AS (MG <20 mm Hg, SVi ≥35 mL/m2, and LVEF ≥50%); "paradoxical" low-flow, low-gradient moderate AS (MG <20 mm Hg, SVi <35 mL/m2, and LVEF ≥50%) and "classical" low-flow, low-gradient moderate AS (MG <20 mm Hg and LVEF <50%). The primary endpoint was all-cause mortality. RESULTS: Of 1,974 patients (age 73 ± 10 years, 51% men) with moderate AS, 788 (40%) had discordant grading, and these patients showed significantly higher mortality rates than patients with concordant moderate AS (P < 0.001). On multivariable analysis, "paradoxical" low-flow, low-gradient (HR: 1.458; 95% CI: 1.072-1.983; P = 0.014) and "classical" low-flow, low-gradient (HR: 1.710; 95% CI: 1.270-2.303; P < 0.001) patterns but not the normal-flow, low-gradient moderate AS pattern were independently associated with all-cause mortality. CONCLUSIONS: Discordant grading is frequently (40%) observed in patients with moderate AS. Low-flow, low-gradient patterns account for an important proportion of the discordant cases and are associated with increased mortality. These findings underline the need for better phenotyping patients with discordant moderate AS.

Staging right heart failure in patients with tricuspid regurgitation undergoing tricuspid surgery.

OBJECTIVES: This study evaluated the prognostic value of staging right heart failure in patients with significant tricuspid regurgitation (TR) undergoing tricuspid valve (TV) surgery. METHODS: Patients with significant TR who underwent TV surgery were divided into 4 right heart failure stages according to the presence of right ventricular (RV) dysfunction and clinical signs of right heart failure: stage 1 was defined as no RV dysfunction and no signs of right heart failure; stage 2 indicated RV dysfunction without signs of right heart failure; stage 3 included RV dysfunction and signs of right heart failure; and stage 4 was defined as RV dysfunction and refractory signs of right heart failure at rest. RESULTS: A total of 278 patients [mean age 64 (12), 49% males] were included, of whom 34 (12%) patients were classified as stages 1 and 2, 141 (51%) as stage 3 and 103 (37%) as stage 4 right heart failure. The majority of patients (91%) had TV surgery concomitant to left-sided valve surgery or coronary artery bypass grafting and 95% underwent TV annuloplasty. Cumulative survival rates were 89%, 78% and 61% at 1 month, 1 year and 5 years, respectively. Stages 1 and 2 and stage 3 were independently associated with better survival compared to stage 4 (hazard ratio: 0.391 [95% confidence interval: 0.186-0.823] and 0.548 [95% confidence interval: 0.369-0.813], respectively). CONCLUSIONS: Patients with significant TR undergoing TV surgery and diagnosed without advanced right heart failure have better survival as compared to patients with right heart failure.

Prognostic value of left atrial reservoir function in patients with severe primary mitral regurgitation undergoing mitral valve repair.

AIMS: Mitral regurgitation (MR) has a significant haemodynamic impact on the left atrium. Assessment of left atrial reservoir strain (LARS) may have important prognostic implications, incremental to left atrial (LA) volume, and conventional parameters of left ventricular (LV) structure and function. This study investigated whether preoperative assessment of LARS by speckle tracking echocardiography is associated with long-term outcomes in patients undergoing mitral valve repair for severe primary MR. METHODS AND RESULTS: Echocardiography was performed prior to mitral valve surgery in 566 patients (age 64 ± 12years, 66% men) with severe primary MR. The study population was subdivided based on a LARS value of 22%, using a spline curve analysis. The primary endpoint was all-cause mortality. During a median follow-up of 7 (4-12) years, 129 (22.8%) patients died. Patients with LARS ≤22% showed significantly higher mortality rates at 1-, 3-, and 5-year follow-up (6%, 12%, and 15%, respectively) when compared with patients with LARS >22% (2%, 3% and 5%, respectively, P < 0.001). Age [hazard ratio (HR): 1.06; 95% confidence interval (CI): 1.03-1.09; P < 0.001], LV global longitudinal strain (HR: 0.92; 95% CI: 0.87-0.98; P = 0.014), and LARS (HR: 0.96; 95% CI: 0.93-0.99; P = 0.014) were independently associated with all-cause mortality. CONCLUSION: Preoperative LARS is independently associated with all-cause mortality in patients undergoing mitral valve repair for primary MR and provides incremental prognostic value over LA volume. LARS might be helpful to guide timing of mitral valve surgery in patients with severe primary MR.

Noninvasive Left Ventricular Myocardial Work in Patients with Chronic Aortic Regurgitation and Preserved Left Ventricular Ejection Fraction.

BACKGROUND: Left ventricular (LV) global longitudinal strain (GLS) has been proposed as a sensitive marker of myocardial damage in patients with chronic severe aortic regurgitation (AR) and preserved LV ejection fraction (LVEF). However, LV GLS does not take into account the afterload. Noninvasive LV myocardial work is a novel parameter of LV myocardial performance, which integrates measurements of myocardial deformation and noninvasive blood pressure (afterload). The aims of this study were (1) to assess noninvasive LV myocardial work in patients with chronic AR and preserved LVEF and its correlation with other echocardiographic parameters, (2) to evaluate changes of LV myocardial work after aortic valve replacement or repair (AVR), and (3) to assess the relationship between LV myocardial work and postoperative LV reverse remodeling. METHODS: Fifty-seven patients (53 ± 16 years; 67% men) with moderate or severe chronic AR and preserved LVEF treated by AVR were included. Noninvasive LV myocardial work indices were measured at baseline and postoperatively (between 2 and 12 months after surgery) and compared with previously reported normal reference ranges. RESULTS: Based on normal reference values, patients with chronic AR and preserved LVEF had preserved or increased values of LV global work index (GWI; 82% and 18%, respectively) and LV global constructive work (GCW; 74% and 25%, respectively) and preserved LV global work efficiency (GWE). Left ventricular GWI and GCW showed a positive correlation with markers of AR severity and parameters of LV systolic function. Left ventricular GWI, GCW, and GWE decreased after AVR (P < .001), without changes in LV global wasted work (P = .28). The postoperative impairment of LV GWI, observed in 28% of patients, was closely associated with reduced LV reverse remodeling. CONCLUSIONS: Noninvasive myocardial work may allow better understanding of myocardial function and energetics than afterload-dependent echocardiographic parameters in chronic AR with preserved LVEF.

Prognostic implications of left atrial dilation in aortic regurgitation due to bicuspid aortic valve.

OBJECTIVE: To investigate the prognostic value of left atrial volume index (LAVI) in patients with moderate to severe aortic regurgitation (AR) and bicuspid aortic valve (BAV). METHODS: 554 individuals (45 (IQR 33-57) years, 80% male) with BAV and moderate or severe AR were selected from an international, multicentre registry. The association between LAVI and the combined endpoint of all-cause mortality or aortic valve surgery was investigated with Cox proportional hazard regression analyses. RESULTS: Dilated LAVI was observed in 181 (32.7%) patients. The mean indexed aortic annulus, sinus of Valsalva, sinotubular junction and ascending aorta diameters were 13.0±2.0 mm/m2, 19.4±3.7 mm/m2, 16.5±3.8 mm/m2 and 20.4±4.5 mm/m2, respectively. After a median follow-up of 23 (4-82) months, 272 patients underwent aortic valve surgery (89%) or died (11%). When compared with patients with normal LAVI (<35 mL/m2), those with a dilated LAVI (≥35 mL/m2) had significantly higher rates of aortic valve surgery or mortality (43% and 60% vs 23% and 36%, at 1 and 5 years of follow-up, respectively, p<0.001). Dilated LAVI was independently associated with reduced event-free survival (HR=1.450, 95% CI 1.085 to 1.938, p=0.012) after adjustment for LV ejection fraction, aortic root diameter, LV end-diastolic diameter and LV end-systolic diameter. CONCLUSIONS: In this large, multicentre registry of patients with BAV and moderate to severe AR, left atrial dilation was independently associated with reduced event-free survival. The role of this parameter for the risk stratification of individuals with significant AR merits further investigation.