Electrocardiographic Markers of Adverse Left Ventricular Remodeling and Myocardial Fibrosis in Severe Aortic Stenosis

The optimal timing for aortic valve replacement (AVR) in aortic stenosis (AS) is still controversial and may be guided by markers of adverse left ventricular (LV) remodeling. We aim to assess electrocardiographic (ECG) strain in relation to LV remodeling and myocardial fibrosis. 83 severe AS patients underwent surgical AVR, with preoperative 12-lead ECG, cardiovascular magnetic resonance with T1 mapping and echocardiography with global longitudinal strain analysis. Collagen volume fraction (CVF) was measured in myocardial biopsies sampled during AVR. Patients with ECG strain had more severe AS, more advanced LV remodeling and evidence of heart failure. Patients with ECG strain had more diffuse fibrosis, as evident by higher mean native T1 values (974.8 ± 34 ms vs. 946.5 ± 28 ms, p < 0.001). ECG strain was the only predictor of increased LV mass index on multivariate regression analysis (OR = 7.10, 95% CI 1.46-34.48, p = 0.02). Patients with persistent ECG strain at 1 year following AVR had more advanced LV remodeling and more histological fibrosis (CVF 12.5% vs. 7.3%, p = 0.009) at baseline assessment. Therefore, ECG strain is a marker of adverse LV remodeling and interstitial myocardial fibrosis. Lack of improvement in ECG strain following AVR indicates more advanced baseline LV injury and higher levels of myocardial fibrosis.

The Early Effects on Tricuspid Annulus and Right Chambers Dimensions in Successful Tricuspid Valve Bicuspidization

BACKGROUND

It is unclear to what degree of tricuspid annulus (TA) reduction is necessary to achieve good postoperative results in surgical bicuspidization. The study aimed to evaluate TA and right heart chamber's dimensions before and after heart surgery; and to compare TA parameters assessed by different modalities.

METHODS

Forty patients underwent mitral valve surgery with or without concomitant tricuspid valve (TV) bicuspidization. Preoperative and postoperative measurements of TA dimensions were performed prospectively using two-dimensional (2D) and three-dimensional (3D) transthoracic echocardiography (TTE). Additionally, preoperative transesophageal echocardiography (TOE) was performed in the operating room prior to surgery.

RESULTS

All patients had no or mild TR immediately after surgery. There was a significant reduction in 2D and 3D parameters of the TV and right chambers in the TV bicuspidization group. However, TV leaflets' tethering parameters did not change significantly. Preoperative 3D TTE measurements were smaller than those obtained through 3D TOE in the operation room, before surgery under general anesthesia. The 2D systolic apical 4Ch diameter and the parasternal short axis diameter mainly represent the 3D minor axis of the TA and are smaller than its 3D major axis.

CONCLUSIONS

Although bicuspidization results in a one-third reduction of the TV area, tethering of the TV leaflets remains unchanged. Moreover, 3D TOE parameters of the TV under general anesthesia are larger than preoperative 3D TTE measurements. Conventional 2D measurements are insufficient for evaluating the maximum diameter of the TA.

A Rare Case of Primary Purulent Pericarditis Caused by Streptococcus constellatus

Background: Bacteria-caused acute pericarditis is a very rare entity. It is usually associated with an underlying infection or compromised immune system. Primary purulent pericarditis in a previously healthy individual is highly unexpected; therefore, it is likely to have a delayed diagnosis and poor outcomes. Case: We report a case of an adult immunocompetent patient with primary bacterial pericarditis caused by a member of the commensal oral flora Streptococcus constellatus. The patient presented with septic shock and cardiac tamponade, and was further complicated with constrictive pericarditis, which was successfully treated with pericardiectomy. Conclusions: Bacterial pericarditis is a fulminant disease with a high mortality and complication rate. Fast recognition and prompt therapy are required to achieve a full recovery.

A Comparison of the Catheter-Based Transapical and Surgical Treatment Modalities for Mitral Paravalvular Leak

Background: There is a lack of studies where the outcomes of mitral paravalvular leak treatment were compared between surgery and catheter-based closure. The aim of this study was to compare the outcomes of re-do surgery with transapical catheter-based paravalvular leak closure. Methods: This is a retrospective observational study at a single institution; 76 patients were included. According to the treatment, two groups were formed: the “Surgical” group (49 patients after re-do surgery) and the “Catheter” group (27 patients after transapical catheter–based treatment). Results: In-hospital myocardial infarction occurred in 9 (18%) cases in the “Surgical” group and none in the “Catheter” group, p = 0.018. Procedure-related life-threatening bleeding occurred in 9 (18%) patients in the “Surgical” group and none in the “Catheter” group, p = 0.018. Nine (18%) patients died in 30 days in the “Surgical” group, and none died in the “Catheter” group, p = 0.039. A mean follow-up was 3.3 years. No difference was found between the groups by the degree of residual paravalvular regurgitation either at discharge or at follow-up. During the follow-up, 19 (39%) patients died in the “Surgical” group and 2 (7%) among the “Catheter” patients. Conclusions: Transapical catheter-based closure of mitral paravalvular leak seems to be a safer treatment procedure than conventional re-do surgery, and the effectiveness of these procedures does not differ.

Exploring myocardial fibrosis in severe aortic stenosis: echo, CMR and histology data from FIB-AS study

Myocardial fibrosis in aortic stenosis is associated with worse survival following aortic valve replacement. We assessed myocardial fibrosis in severe AS patients, integrating echocardiographic, cardiovascular magnetic resonance (CMR) and histological data. A total of 83 severe AS patients (age 66.4 ± 8.3, 42% male) who were scheduled for surgical AVR underwent CMR with late gadolinium enhancement and T1 mapping and global longitudinal strain analysis. Collagen volume fraction was measured in myocardial biopsies (71) that were sampled at the time of AVR. Results. CVF correlated with imaging and serum biomarkers of LV systolic dysfunction and left side chamber enlargement and was higher in the sub-endocardium compared with midmyocardium (p<0.001). CVF median values were higher in LGE-positive versus LGE-negative patients [28.7% (19-33) vs 20.7% (15-30), respectively, p=0.040]. GLS was associated with invasively (CVF; r=-0.303, p=0.013) and non-invasively (native T1; r=-0.321, p<0.05) measured myocardial fibrosis. GLS and native T1 correlated with parameters of adverse LV remodelling, systolic and diastolic dysfunction and serum biomarkers of heart failure and myocardial injury. Conclusion. Our data highlight the role of myocardial fibrosis in adverse cardiac remodelling in AS. GLS has potential as a surrogate marker of myocardial fibrosis, and high native T1 and low GLS values differentiated patients with more advanced cardiac remodelling.

Rescue transventricular off-pump mitral valve repair with artificial neochords for acute mitral regurgitation due to postinfarction papillary muscle rupture

Background

We report 3 cases of rescue transventricular off-pump mitral valve (MV) repair in high-risk patients with acute mitral regurgitation (MR) due to post–myocardial infarction (MI) papillary muscle rupture (PMR).

Methods

The 3 patients presented with acute inferior ST elevation myocardial infarction, cardiogenic shock, and pulmonary edema. Their preoperative peak troponin I levels were 1909 ng/L, 16,963 ng/L, and 8299 ng/L. All 3 patients underwent successful percutaneous intervention to the culprit coronary artery, and antiplatelet therapy was initiated. All patients required inotropic support and had an intra-aortic balloon pump inserted preoperatively. Transesophageal echocardiography (TEE) demonstrated severe eccentric MR due to the leaflet prolapse secondary to PMR. The patients’ estimated EuroSCORE II scores were 16.03%, 16.68%, and 7.81%, and their Society of Thoracic Surgeons scores were 14.77%, 18.24%, and 9.8%, respectively. All 3 patients underwent urgent transventricular off-pump MV repair using artificial chords, with 2 or 3 three neochords implanted. The duration of operation was <2 hours, and intraoperative and postoperative drainage was minimal in all cases. MV function was assessed by qualitative and semiquantitative TEE.

Results

Intraoperative MR reduction to a mild level was achieved in all 3 patients. All patients had moderate MR at discharge, likely due to left ventricular remodeling. Severe MR recurred in all patients, at 5, 4, and 2 months of follow-up, respectively. All 3 patients underwent an elective MV reoperation via conventional approach.

Conclusions

Off-pump transventricular MV repair may offer a safe and feasible alternative to stabilize high-risk patients with acute MR due to post-MI PMR. Although early MR recurrence is concerning, urgent transventricular MV repair may serve as a bridge to conventional surgery in such unstable patients.

Midterm results of transventricular mitral valve repair: Single-center experience

OBJECTIVE

The study objective was to evaluate the midterm outcomes of transventricular mitral valve repair and its association with the initial anatomy of the mitral valve.

METHODS

This nonrandomized observational study included 88 patients (mean age, 60 years; 69% were men) who underwent transventricular mitral valve repair for severe degenerative mitral regurgitation between 2011 and 2017. Mitral valve function was assessed by echocardiography at 1 and 6 months and annually after the procedure. According to the location of mitral valve pathology, all patients were stratified into 4 anatomic types (A, B, C, and D). Results were assessed using Kaplan-Meier method, mixed-effects continuation ratio model, and multivariable Cox regression.

RESULTS

Median follow-up of 42 months (interquartile range, 27-55) was complete for 83 patients (94.3%). There were 3 late deaths: 2 cardiac and 1 noncardiac. Recurrent mitral regurgitation greater than 2+ was observed in 29 patients (33%), and 18 patients (20.5%) underwent repeat surgery. Device success was 82% in type A at 6 months and thereafter; 87%, 85%, and 75% at 6, 12, and 36 months in type B, respectively; and 53% at 1 month and 20% at 24 months in type C. Probability of postoperative mitral regurgitation progression was higher in patients with greater preoperative left ventricular end-diastolic diameter, type B pathology, and type C pathology (P < .05). Risk factors of mitral regurgitation recurrence included increased left ventricle size (hazard ratio, 1.11; 95% confidence interval, 1.04-1.20; P = .001) and type C pathology (hazard ratio, 5.99; 95% confidence interval, 1.87-19.21; P = .003).

CONCLUSIONS

Initial acceptable mitral regurgitation reduction after transventricular mitral valve repair of isolated P2 prolapse was possible but found durable in only 82% at 3 years. Higher risk of mitral regurgitation recurrence occurred with complex degenerative pathology.

Prognostic value of myocardial fibrosis in severe aortic stenosis: study protocol for a prospective observational multi-center study (FIB-AS)

Background

Adverse cardiac remodeling with a myocardial fibrosis as a key pathophysiologic component may be associated to worse survival in aortic stenosis (AS) patients. Therefore, with the application of advanced cardiac imaging we aim to investigate left ventricular myocardial fibrosis in severe AS patients undergoing aortic valve replacement (AVR) and determine its impact with post-intervention clinical outcomes.

Methods

In a prospective, observational, cohort study patients with severe AS scheduled either for surgical or transcatheter AVR will be recruited from two tertiary heart centers in Denmark and Lithuania. All patients will receive standard of care in accordance with the current guidelines and will undergo additional imaging testing before and after AVR: echocardiography with deformation analysis and cardiovascular magnetic resonance (CMR) with T1 parametric mapping. Those undergoing surgical AVR will also have a myocardial biopsy sampled at the time of a surgery for histological validation. Patients will be recruited over a 2-year period and followed up to 2 years to ascertain clinical outcomes. Follow-up CMR will be performed 12 months following AVR, and echocardiography with deformation analysis will be performed 3, 12, and 24 months following AVR. The study primary outcome is a composite of all-cause mortality and major adverse cardiovascular events.

Discussion

Despite continuous effort of research community there is still a lack of early predictors of left ventricular decompensation in AS, which could improve patient risk stratification and guide the optimal timing for aortic valve intervention, before irreversible left ventricular damage occurs. Advanced cardiac imaging and CMR derived markers of diffuse myocardial fibrosis could be utilized for this purpose. FIB-AS study is intended to invasively and non-invasively assess diffuse myocardial fibrosis in AS patients and investigate its prognostic significance in post-interventional outcomes. The results of the study will expand the current knowledge of cardiac remodeling in AS and will bring additional data on myocardial fibrosis and its clinical implications following AVR.

Ethics/dissemination

The study has full ethical approval and is actively recruiting patients. The results will be disseminated through scientific journals and conference presentations.

Trial registration

ClinicalTrials.govNCT03585933. Registered on 02 July 2018.