Cardiac MRI-Enriched Phenomapping Classification and Differential Treatment Outcomes in Patients With Ischemic Cardiomyopathy

BACKGROUND

Significant controversy continues to confound patient selection and referral for revascularization and mitral valve intervention in patients with ischemic cardiomyopathy (ICM). Cardiac magnetic resonance (CMR) enables comprehensive phenotyping with gold-standard tissue characterization and volumetric/functional measures. Therefore, we sought to determine the impact of CMR-enriched phenomapping patients with ICM to identify differential outcomes following surgical revascularization and surgical mitral valve intervention (sMVi).

METHODS

Consecutive patients with ICM referred for CMR between 2002 and 2017 were evaluated. Latent class analysis was performed to identify phenotypes enriched by comprehensive CMR assessment. The primary end point was death, heart transplant, or left ventricular assist device implantation. A multivariable Cox survival model was developed to determine the association of phenogroups with overall survival. Subgroup analysis was performed to assess the presence of differential response to post-magnetic resonance imaging procedural interventions.

RESULTS

A total of 787 patients were evaluated (63.0±11.2 years, 24.8% women), with 464 primary events. Subsequent surgical revascularization and sMVi occurred in 380 (48.3%) and 157 (19.9%) patients, respectively. Latent class analysis identified 3 distinct clusters of patients, which demonstrated significant differences in overall outcome (P<0.001). Latent class analysis identified differential survival benefit of revascularization in patients as well as patients who underwent revascularization with sMVi, based on phenogroup classification, with phenogroup 3 deriving the most survival benefit from revascularization and revascularization with sMVi (hazard ratio, 0.61 [0.43-0.88]; P=0.0081).

CONCLUSIONS

CMR-enriched unsupervised phenomapping identified distinct phenogroups, which were associated with significant differential survival benefit following surgical revascularization and sMVi in patients with ICM. Phenomapping provides a novel approach for patient selection, which may enable personalized therapeutic decision-making for patients with ICM.

Prevalence, Characteristics, and Outcomes of Infective Endocarditis Readmissions in Patients With Variables Associated With Liver Disease in the United States

Infective endocarditis (IE) is common in patients with liver disease. Outcomes of IE in patients with liver disease are limited. We aimed to investigate IE outcomes in patients with variables associated with liver disease in the USA. We used the 2017 National Readmission Database to identify index admission of adults with IE, based on the International Classification of Disease, 10th revision codes. The primary outcome was 30-day readmission. Secondary outcomes were mortality and predictors of hospital readmission. We identified 40,413 IE admissions. Patients who were readmitted were more likely to have a history of HCV (19.4 vs 12.3%, P < .001), hyponatremia (25 vs 21%, P < .001), and thrombocytopenia (20.3 vs 16.3%, P < .001). After adjusting for age, hypertension, heart failure, diabetes mellitus, and end stage renal disease, hyponatremia (odds ratio (OR) 1.25; 95% confidence intervals [CI]: 1.17-1.35; P < .001) and thrombocytopenia (OR 1.16; 95% CI: 1.08-1.24; P < .001) correlated with higher odds of 30-day readmission. Mortality was higher among patients with hyponatremia (29 vs 22%, P < .001), thrombocytopenia (29 vs 17%, P < .001), coagulopathy (12 vs 5%, P < .001), cirrhosis (6 vs 4%, P < .001), ascites (7 vs 3%, P < .001), liver failure (18 vs 3%, P < .001), and portal hypertension (3 vs 1.5%, P < .001).

Impact of Bariatric Surgery on Left Ventricular Structure and Function

BACKGROUND

Obesity leads to an increased risk of cardiovascular disease morbidity and death, including heart failure. Bariatric surgery has been proven to be the most effective long-term weight management treatment. This study investigated the changes in cardiac structure and function after bariatric surgery, including left ventricular global longitudinal strain.

METHODS AND RESULTS

There were 398 consecutive patients who underwent bariatric surgery with pre- and postoperative transthoracic echocardiographic imaging at a US health system between 2004 and 2019. We compared cardiovascular risk factors and echocardiographic parameters between baseline and follow-up at least 6 months postoperatively. Along with decreases in weight postoperatively, there were significant improvements in cardiovascular risk factors, including reduction in systolic blood pressure levels from 132 mm Hg (25th-75th percentile: 120-148 mm Hg) to 127 mm Hg (115-140 mm Hg; P=0.003), glycated hemoglobin levels from 6.5% (5.9%-7.6%) to 5.7% (5.4%-6.3%; P<0.001), and low-density lipoprotein levels from 97 mg/dL (74-121 mg/dL) to 86 mg/dL (63-106 mg/dL; P<0.001). Left ventricular mass decreased from 205 g (165-261 g) to 190 g (151-236 g; P<0.001), left ventricular ejection fraction increased from 58% (55%-61%) to 60% (55%-64%; P<0.001), and left ventricular global longitudinal strain improved from -15.7% (-14.3% to -17.5%) to -18.6% (-16.0% to -20.3%; P<0.001) postoperatively.

CONCLUSIONS

This study has shown the long-term impact of bariatric surgery on cardiac structure and function, with reductions in left ventricular mass and improvement in left ventricular global longitudinal strain. These findings support the cardiovascular benefits of bariatric surgery.

Contemporary Trends in Clinical Characteristics, Therapeutic Strategies and Outcomes in Patients Aged 80 Years and Older Presenting with non-ST Elevation Myocardial Infarctions in the United States

The current guidelines for the management and treatment of acute coronary syndromes do not fully consider the role of age in guiding medical or invasive management. We investigated the characteristics, management strategies, and clinical outcomes of patients aged 80 years and older presenting with non-ST elevation myocardial infarction (NSTEMI). A cohort study using the nationwide inpatient sample database of patients aged 80 years and older presenting with NSTEMI in the United States between 2012 to 2018 was performed. About 24.2% (151,472/625,916) of NSTEMI patients were 80 years and older. Older patients (≥80 years) had higher in-hospital mortality and cardiovascular complications compared to younger patients (odds ratio (OR) 1.79, 95% confidence intervals (CI) 1.71-1.88, P < 0.001). Among older patients, conservative medical management was associated with higher inpatient mortality compared to percutaneous coronary intervention (PCI) (OR 2.3, 95% CI 2.18-2.41, P < 0.001) or coronary artery bypass graft (CABG) (OR 1.9, 95% CI 1.76-2.09, P < 0.001). The highest mortality rate was observed in older patients who underwent both PCI and CABG, followed by those treated conservatively and those undergoing coronary angiography without revascularization. This study provides valuable insights into the clinical characteristics and outcomes of elderly patients presenting with NSTEMI in the United States. The results emphasize the importance of a tailored approach to the management of ACS in elderly patients and the need for improved revascularization strategies to reduce in-hospital mortality and adverse cardiovascular outcomes. Therefore, the clinician should tailor the management of older patients presenting with NSTEMI.

Impact of Age and Sex on Left Ventricular Remodeling in Patients With Aortic Regurgitation

BACKGROUND

Current guidelines for aortic regurgitation (AR) recommend the same linear left ventricular (LV) dimension for intervention regardless of age and sex.

OBJECTIVES

The purpose of this study was to evaluate the impact of age and sex on the degree of LV remodeling and outcomes.

METHODS

We included consecutive patients with severe AR who were serially monitored by echocardiogram between 2010 and 2016. The 2 main endpoints were as follows: 1) LV end-systolic volume indexed to body surface area (LVESVi) and LV end-diastolic volume indexed to body surface area; and 2) adverse events (AE). We evaluated the longitudinal rate of LV remodeling and determined the association between LV volume and AE by age and sex.

RESULTS

A total of 525 adult patients (26% women) with a median echocardiogram follow-up of 2.0 years (IQR: 1.0-3.6 years) were included. At baseline, older patients (age ≥60 years) had smaller LV volumes compared with younger patients (age <60 years), eg, the mean LVESVi was 27.3 mL/m² vs 32.3 mL/m², respectively. Similarly, women had smaller LV volumes compared with men (mean LVESVi was 23.3 mL/m² vs 32.4 mL/m²). On serial evaluation, older patients and women maintained smaller LV volumes compared with younger patients and men, respectively. There were 210 (40%) AE during follow-up. The optimal discriminatory threshold for AE varies by age and sex, eg, the LVESVi threshold was highest for young men (50 mL/m²), intermediate for older men (35 mL/m²), and lowest for women (27 mL/m²).

CONCLUSIONS

On serial evaluation, older patients and women with chronic AR maintained smaller LV volumes than younger patients and men, respectively, and develop AE at lower LV volumes.

Echocardiographic profiles and hemodynamic response after vasopressin initiation in septic shock: A cross-sectional study

PURPOSE

Vasopressin, used as a catecholamine adjunct, is a vasoconstrictor that may be detrimental in some hemodynamic profiles, particularly left ventricular (LV) systolic dysfunction. This study tested the hypothesis that echocardiographic parameters differ between patients with a hemodynamic response after vasopressin initiation and those without a response.

METHODS

This retrospective, single-center, cross-sectional study included adults with septic shock receiving catecholamines and vasopressin with an echocardiogram performed after shock onset but before vasopressin initiation. Patients were grouped by hemodynamic response, defined as decreased catecholamine dosage with mean arterial pressure ≥ 65 mmHg six hours after vasopressin initiation, with echocardiographic parameters compared. LV systolic dysfunction was defined as LV ejection fraction (LVEF) <45%.

RESULTS

Of 129 included patients, 72 (56%) were hemodynamic responders. Hemodynamic responders, versus non-responders, had higher LVEF (61% [55%,68%] vs. 55% [40%,65%]; p = 0.02) and less-frequent LV systolic dysfunction (absolute difference  -16%; 95% CI -30%,-2%). Higher LVEF was associated with higher odds of hemodynamic response (for each LVEF 10%, response OR 1.32; 95% CI 1.04-1.68). Patients with LV systolic dysfunction, versus without LV systolic dysfunction, had higher mortality risk (HR(t) = e^[0.81-0.1*t]; at t = 0, HR 2.24; 95% CI 1.08-4.64).

CONCLUSIONS

Pre-drug echocardiographic profiles differed in hemodynamic responders after vasopressin initiation versus non-responders.

Prognostic impact of left ventricular systolic dysfunction in patients with mixed aortic valve disease undergoing aortic valve replacement

BACKGROUND

The implications of left ventricular remodeling and dysfunction before and after aortic valve replacement (AVR) for mixed aortic valve disease (MAVD) are not well understood. This study aims to evaluate the impact of AVR on left ventricular (LV) systolic function in MAVD, and determine the prognostic value of postoperative LV global longitudinal strain (LV-GLS) and LV ejection fraction (LVEF).

METHODS

We retrospectively assessed 489 consecutive patients with MAVD (defined as at least moderate aortic stenosis and at least moderate aortic regurgitation) and baseline LVEF ≥50%, who underwent AVR between February 2003 and August 2018. All patients had baseline echocardiography, whereas 192 patients underwent postoperative echocardiography between 3 and 18 months after AVR. The primary endpoint was all-cause mortality.

RESULTS

Mean age was 65 ± 15 years, and 65% were male. AVR in MAVD patients has a neutral effect on LV systolic function quantitated by LVEF and LV-GLS. During a median follow-up period of 5.8 years, 65 patients (34%) of 192 patients with follow-up echocardiography died. The patients with postoperative LVEF ≥50% had better survival than those with postoperative LVEF <50% (P < .001). Furthermore, among patients with postoperative LVEF ≥50%, mortality differed between patients with postoperative LV-GLS worse than -15% and those with postoperative LV-GLS better than -15% (P < .001).

CONCLUSIONS

In patients with MAVD who underwent AVR, the mean postoperative LV-GLS and LVEF remain at a similar value to baseline. However, worse postoperative LV-GLS and LVEF were both independently associated with higher mortality in this population.

Diagnostic performance of contemporary transesophageal echocardiography with modern imaging for infective endocarditis

Background

Infective endocarditis (IE) is associated with high morbidity and mortality. Following an initial negative transesophageal echocardiogram (TEE), high clinical suspicion warrants repeat examination. We evaluated the diagnostic performance of contemporary TEE imaging for IE.

Methods

This retrospective cohort study included patients ≥18 years old undergoing ≥2 TEEs within 6 months, with confirmed diagnosis of IE based on Duke criteria, 70 in 2011 and 172 in 2019, were included. We compared the diagnostic performance of TEE for IE in 2019 versus 2011. The primary endpoint was the sensitivity of initial TEE to detect IE.

Results

Sensitivity of the initial TEE to detect endocarditis was 85.7% versus 95.3%, in 2011 and 2019, respectively (P=0.01). On multivariable analysis, initial TEE more frequently detected IE in 2019, compared to 2011 [odds ratio (OR): 4.06, 95% confidence intervals (CIs): 1.41-11.71, P=0.01]. Improved diagnostic performance was driven by improved detection of prosthetic valve infective endocarditis (PVIE), sensitivity 70.8% in 2011 versus 93.7% (P=0.009) in 2019. In 2019, TEEs more frequently utilized probes with higher frame rates/resolution, than 2011 (P<0.001). Three dimensional (3D) technology was utilized in 97.2% of initial TEEs in 2019, compared to 70.5% in 2011 (P<0.001).

Conclusions

Contemporary TEE was associated with improved diagnostic performance for endocarditis, driven by improved sensitivity for PVIE.

Novel Multi-Parametric Mitral Annular Calcification Score Predicts Outcomes in Mitral Valve Dysfunction

The objective of the study was to construct a multi-parametric mitral annular calcification (MAC) score using computed tomography (CT) features for prediction of outcomes in patients undergoing mitral valve surgery. We constructed a multi-parametric MAC score, which ranges between 2 and 12, and consists of Agatston calcium score (1 point: <1000 Agatston units (AU); 2 points: 1000-<3000 AU; 3 points: 3000-5000 AU; 4 points: >5000 AU), quantitative MAC circumferential angle (1 point: <90°; 2 points: 90-<180°; 3 points: 180-<270°; 4 points: 270-360°), involvement of trigones (1 point: 1 trigone; 2 points: both trigones), and 1 point each for myocardial infiltration and left ventricular outflow tract extension/involvement of aorto-mitral curtain. The association between MAC score and clinical outcomes was evaluated. The study cohort consisted of 334 patients undergoing mitral valve surgery (128 mitral valve repairs, 206 mitral valve replacements) between January 2011 and September 2019, who had both non-contrast gated CT scan and evidence of MAC. The mean age was 72 ± 11 years, with 58% of subjects being female. MAC score was a statistically significant predictor of total operation time (P<0.001), cross-clamp time (P = 0.001) and in-hospital complications (P = 0.003). Additionally, MAC score was a significant predictor of time to all-cause death (P = 0.046). A novel multi-parametric score based on CT features allowed systematic assessment of MAC, and predicted clinical outcomes in patients with mitral valve dysfunction undergoing mitral valve surgery.

Post-systolic shortening index by echocardiography evaluation of dyssynchrony in the non-dilated and hypertrophied left ventricle

Background

Post-systolic shortening index (PSI) is defined as myocardial shortening that occurs after aortic valve closure, and is an emerging measure of regional LV contractile dysfunction. PSI measurement variability amongst software vendor and its relationship with mechanical dyssynchrony and mechanical dispersion index (MDI) remains unknown. We evaluated PSI by speckle-tracking echocardiography from several vendors in patients with increased left ventricular wall thickness, and associations with MDI.

Methods

This is a prospective cross-sectional study of 70 patients (36 hypertrophic cardiomyopathy [HCM], 18 cardiac amyloidosis and 16 healthy controls) undergoing clinically indicated echocardiography. PSI was measured using QLAB/aCMQ (Philips), QLAB/LV auto-trace (Philips), EchoPAC (GE), Velocity Vector Imaging (Siemens), and EchoInsight (EPSILON) software packages, and calculated as 100% × (post systolic strain − end-systole strain)/post systolic strain.

Results

There was a significant difference in mean PSI among controls 2.1±0.6%, HCM 6.1±2.6% and cardiac amyloidosis 6.8±2.7% (p&lt;0.001). Variations between software vendors were significant in patients with pathologic increases in LV wall thickness (for HCM p=0.03, for amyloidosis p=0.008), but not in controls (p=0.11), as seen in Figure 1. Furthermore, there were moderate correlations between PSI and both MDI (r=0.77) and left ventricular global longitudinal strain (r=0.69), as seen in Figure 2.

Conclusion

PSI was greater in HCM and cardiac amyloidosis patients than controls, and a valuable tool for dyssynchrony evaluation, with moderate correlations to MDI and strain. However, there were significant variations in PSI measurements by software vendor especially in patients with pathological increase in LV wall thickness, suggesting that separate vendor-specific thresholds for abnormal PSI are required.

Funding Acknowledgement

Type of funding sources: None.

Impact of Opioid Epidemic on Infective Endocarditis Outcomes in the United States: From the National Readmission Database

Infective endocarditis (IE) is associated with marked morbidity and mortality in the United States and parallels the opioid pandemic. Few studies explore this interaction and its effect on clinical outcomes. We analyzed contemporary patients admitted with IE to determine predictors of readmission in the United States. The 2017 National Readmission Database was used to identify index admissions in adults with the diagnosis of IE, based on the International Classification of Disease, 10th Revision codes. The primary outcome of interest was 30-day readmission. Secondary outcomes were mortality, hospital charges, and predictors of hospitalization readmission. Of 40,413 index admissions for IE, 5,558 patients (13.8%) were readmitted within 30 days. Patients who were readmitted were younger (55 ± 20 vs 61 ± 19 years, p <0.001) and more likely to have end-stage renal disease (12.2% vs 10.5%, p <0.001), hepatitis C virus (19.4% vs 12.6%, p <0.001), HIV (1.8% vs 1.2%, p = 0.001), opioid abuse (23.9% vs 15%, p <0.001), cocaine use (7.3% vs 4.4%, p <0.001), and other substance abuse (8.5 vs 5.6, p <0.001). Patients readmitted were less likely to have diabetes mellitus (27.8% vs 29.4%, p = 0.01), hypertension (56.9% vs 64%, p <0.001), heart failure (37.7% vs 40%, p <0.001), chronic kidney disease (31.2% vs 32%, p <0.001), and peripheral vascular disease (3.6% vs 4.6%, p = 0.001). The median cost of index admission for the total cohort was $84,325 (39,922 to 190,492). After adjusting for age, diabetes mellitus, heart failure, hypertension, and end-stage renal disease, opioid abuse (odds ratio [OR] 1.34; 95% confidence interval [CI] 1.23 to 1.46; p <0.001), cocaine use (OR 1.32; 95% CI 1.17 to 1.48; p <0.001), other substance abuse (OR 1.16; 95% CI 1.04 to 1.30; p = 0.008), and hepatitis C virus (OR 1.32; 95% CI 1.21 to 1.43; p <0.001) correlated with higher odds of 30-day readmission. These factors may present targets for future intervention.

Cardiovascular Manifestations, Imaging, and Outcomes in Systemic Lupus Erythematosus: An Eight-Year Single Center Experience in the United States

Systemic lupus erythematosus (SLE) is a challenging autoimmune and multi-system condition. With advances in cardiovascular screening and therapies for SLE patients, we evaluated the cardiovascular characteristics, multi-modality imaging, and outcomes of SLE at our tertiary referral center over an 8 year period. Consecutive patients from our SLE registry from April 2012 to March 2020 were retrospectively analyzed. Data pertaining to cardiovascular manifestations, investigations, management, and outcomes were assessed. We studied 258 SLE patients (mean age 42.2 ± 14.7 years); 233 (90.3%) were female. The main cardiac manifestations at index SLE clinic were pericardial disease in 33.3%, valve disease in 18%, cardiomyopathy in 9.6%, and stroke in 7.4%. During a mean follow-up of 3.0 ± 2.2 years after index SLE clinic, there were 5 (1.9%) deaths, 24 (9.3%) cardiovascular events, and 44 (17.1%) SLE-related hospitalizations. A history of stroke and hypertension were independently associated with cardiovascular events, hazard ratio (HR) (95% confidence intervals (CI)) of 5.38 (1.41-20.6) and 3.31 (1.02-10.7), respectively, while younger age and lower albumin predicted SLE-related hospitalizations. Cardiovascular manifestations are prevalent in SLE, especially for pericardial, valvular, and atherosclerotic diseases. With contemporary SLE and cardiovascular management, subsequent adverse cardiovascular events were infrequent in this study.

Association of pepper intake with all-cause and specific cause mortality - A systematic review and meta-analysis

OBJECTIVE

To conduct a comprehensive systematic review and meta-analysis to compare mortality and other clinical outcomes associated with chili pepper (CP) consumption versus no/rare consumption of CP.

METHODS

A comprehensive search was performed using Ovid, Cochrane, Medline, EMBASE, and Scopus from inception till January 16, 2020. Observational studies and randomized controlled trials were included, while pediatric/animal studies, letters/case reports, reviews, abstracts, and book chapters were excluded. All-cause mortality was studied as the primary outcome. Cardiovascular mortality, cancer-related deaths and cerebrovascular accidents were studied as secondary outcomes.

RESULTS

From 4729 studies, four studies met the inclusion criteria. Random effects pooled analysis showed that all-cause mortality among CP consumers was lower, compared to rare/non-consumers, with a hazard ratio (HR) of 0.87 [95% CI: 0.85-0.90; p<0.0001; I 2=1%]. HR for cardiovascular mortality was 0.83 [95% CI: 0.74-0.95; p = 0.005, I 2=66%] and for cancer-related mortality as 0.92 [95% CI: 0.87-0.97; p = 0.001; I 2=0%]. However, the HR for CVA was 0.78 [95% CI: 0.56-1.09; p = 0.26; I2 =60%]. The mode and amount of CP consumption varied across the studies, and data were insufficient to design an optimal strategy guiding its intake.

CONCLUSION

Regular CP consumption was associated with significantly lower all-cause, cardiovascular, and cancer-related mortalities. However, based on current literature, it is difficult to derive a standardized approach to guide the optimal mode and amount of CP consumption. This warrants well-designed prospective studies to further investigate the potential health benefits of CP consumption.

Physical and physiological effects of dobutamine stress echocardiography in low-gradient aortic stenosis

Dobutamine stress echocardiography (DSE) is a useful tool for assessing low-gradient significant aortic stenosis (AS) and contractile reserve (CR), but its prognostic utility has become controversial in recent studies. We evaluated the impact of DSE on aortic valve physiological, structural, and left ventricular parameters in low-gradient AS. Consecutive patients undergoing DSE for low-gradient AS evaluation from September 2010 to July 2016 were retrospectively studied, and DSE findings were divided into four groups: with and without severe AS and/or CR. Relationships between left ventricular chamber quantification, CR, aortic valve Doppler during DSE, and calcium score [by computerized tomography (CT)] were analyzed. There were 258 DSE studies performed on 243 patients, mean age 77.6 ± 10.8 yr and 183 (70.1%) were males. With increasing dobutamine dose, apart from systolic blood pressure, left ventricular ejection fraction, flow, cardiac power output, and longitudinal strain magnitude, along with aortic valve area and mean aortic gradient were all significantly increased (P < 0.05). Flow and mean gradient increased in both the presence and absence of CR, whereas stroke volume and aortic valve area increased mainly in those with CR only. The aortic valve area increased in both patients with low and high calcium scores; however, the baseline area was lower in those with a higher calcium score. During DSE, aortic valve area increases with increase in aortic valve gradient. Higher calcium score is associated with lower baseline aortic valve area, but the aortic valve area still increases with dobutamine even in presence of a high calcium score.NEW & NOTEWORTHY We show that even in most severe aortic stenosis, there is some residual valve pliability. This suggests that a complete loss of pliability is not compatible with survival.

Defining the reference range for right ventricular systolic strain by echocardiography in healthy subjects: A meta-analysis

BACKGROUND

Right ventricular (RV) systolic strain has recently demonstrated prognostic value in various cardiovascular diseases. Despite this, the reference range including the lower limit of normal (LLN) and factors associated with RV strain measurements are not well-established. This meta-analysis aimed to determine the mean and LLN of two- (2D) and three-dimensional (3D) right ventricular global (RVGLS), free wall (RVFWLS) and interventricular septal wall (IVSLS) longitudinal strains in healthy individuals and factors that affect strain measurements.

METHODS

In this meta-analysis, Pubmed, Embase and Cochrane databases were searched until 31 July 2020 for eligible studies reporting RVGLS, RVFWLS and/or IVSLS in at least 30 healthy subjects. We pooled the means and LLNs of RV strains by two- (2D) and three- (3D) dimensional echocardiography, and performed meta-regression analyses.

RESULTS

From 788 articles screened, 45 eligible studies totaling 4439 healthy subjects were eligible for analysis. Pooled means and LLNs with 95% confidence intervals for 2D- RV strains were RVGLS -23.4% (-24.2%, -22.6%) and -16.4% (-17.3%, -15.5%) in 27 studies; RVFWLS -26.9% (-28.0%, -25.9%) and -18.0% (-19.2%, -16.9%) in 32 studies; and IVSLS -20.4% (-22.0%, -18.9%) and -11.5% (-13.6%, -9.6%) in 10 studies, and similar results for 3D- RV strains. Right ventricular fractional area change and vendor software were associated with 2D-RVGLS and RVFWLS means and LLNs.

CONCLUSION

We reported the pooled means and LLNs of RV systolic strains in healthy subjects, to define thresholds for abnormal, borderline and normal strains. Important factors associated with RV systolic strains include right ventricular fractional area change and vendor software.

Diagnostic and Prognostic Performance of Aortic Valve Calcium Score with Cardiac CT for Aortic Stenosis: A Meta-Analysis

PURPOSE

To evaluate the diagnostic and prognostic performance of the aortic valve calcium score (AVCS) with the Agatston method using CT in aortic stenosis (AS) and to assess mean AVCS according to AS severity.

MATERIALS AND METHODS

In this meta-analysis, PubMed, Embase, and Cochrane were searched from January 1, 1980, to December 31, 2020, for studies reporting sensitivity and specificity of AVCS using CT for severe AS, mean AVCS in severe and nonsevere AS, and/or hazard ratios for all-cause mortality in AS. Data were pooled using random effect models and meta-analysis software.

RESULTS

Twelve studies (six diagnostic, three prognostic, and 10 reporting mean AVCS by AS severity) were included for analysis. A total of 4101 patients (2255 with severe AS) were described in these 12 studies. Pooled sensitivity and specificity were 82% (95% CI: 80, 84) and 78% (95% CI: 75, 81), respectively. Pooled mean AVCS were 3219 (95% CI: 2795, 3643) for severe AS, compared with 1252 (95% CI: 863, 1640) for nonsevere AS, 1808 (95% CI: 1163, 2452) for moderate AS, and 584 (95% CI: 309, 859) for mild AS. Pooled hazard ratio for AVCS as a binary threshold to predict mortality was 2.11 (95% CI: 1.11, 4.12).

CONCLUSION

AVCS had moderate to high sensitivity and specificity for identifying severe AS and was also a useful prognostic imaging marker in AS. Mean AVCS categorized by AS severity may help guide clinical management.Keywords CT, Aortic Valve, Valves, Meta-Analysis© RSNA, 2021.

Left Ventricular Longitudinal Strain in Characterization and Outcome Assessment of Mixed Aortic Valve Disease Phenotypes

OBJECTIVES

The aims of this study were to characterize the interplay between mixed aortic valve disease (MAVD) phenotypes (defined by concomitant severities of aortic stenosis and aortic regurgitation) and left ventricular global longitudinal strain (LV-GLS), and to assess the prognostic utility of LV-GLS in MAVD.

BACKGROUND

Little is known about the way LV-GLS separates MAVD phenotypes and if it is associated with their outcomes.

METHODS

This observational cohort study evaluated 783 consecutive adult patients with left ventricular ejection fraction ≥50% and MAVD, which was defined as coexisting with at least moderate aortic stenosis and at least moderate aortic regurgitation. We measured the conventional echocardiographic variables and average LV-GLS from apical long, 2- and 4-chamber views. The primary endpoint was all-cause mortality.

RESULTS

Mean age of patients was 69 ± 15 years, and 58% were male. Mean LV-GLS was -14.7 ± 2.9%. In total, 458 patients (59%) underwent aortic valve replacement at a median period of 50 days (25th to 75th percentile range: 6 to 560 days). During a median follow-up period of 5.6 years (25th to 75th percentile range: 1.8 to 9.4 years), 391 patients (50%) died. When stratified patients into tertiles according to LV-GLS values, patients with worse LV-GLS had worse outcomes (p < 0.001). LV-GLS was independently associated with mortality (hazard ratio: 1.09; 95% confidential intervals: 1.04 to 1.14; p < 0.001), with the relationship between LV-GLS and mortality being linear.

CONCLUSIONS

LV-GLS is associated with all-cause mortality. LV-GLS may be useful for risk stratification in patients with MAVD.

Impact of left atrial strain mechanics on exercise intolerance and need for septal reduction therapy in hypertrophic cardiomyopathy

AIMS

We sought to assess the relationship between left atrial (LA) strain mechanics and exercise intolerance, and to evaluate the prognostic impact of LA strain mechanics on clinical deterioration necessitating septal reduction therapy in hypertrophic cardiomyopathy (HCM).

METHODS AND RESULTS

Consecutive HCM patients who underwent exercise stress echocardiography and cardiopulmonary exercise testing on the same day between October 2015 and April 2019 were enrolled prospectively. LA strain mechanics were analysed using speckle tracking echocardiography. LA stiffness was calculated as the ratio of E/e' ratio to LA reservoir strain. The study cohort was divided into four groups based on the quartile of percent-predicted peak VO2, and exercise intolerance was defined as the lowest quartile (≤51%). Of 532 patients studied (mean age: 51 ± 15 years, 42% female), 138 patients demonstrated exercise intolerance. As exercise capacity worsened, LA strain mechanics worsened along a continuum (P < 0.001). LA contractile strain with a cut-off of -13.9% was optimal at identifying exercise intolerance. On multivariable analysis, worse LA contractile strain was an independent predictor for exercise intolerance (P = 0.002). Of patients with left ventricular outflow tract obstruction, patients with LA stiffness worse than the median value (≥0.41) were significantly more likely to require septal reduction therapy than those with better LA stiffness (P = 0.026).

CONCLUSION

Worse LA contractile strain was an independent predictor for exercise intolerance in HCM. Patients with worse LA stiffness had a higher probability of clinical deterioration necessitating septal reduction therapy.

Determining the thresholds for abnormal left ventricular strains in healthy subjects by echocardiography: a meta-analysis

Background

Left ventricular global longitudinal strain (LVGLS), circumferential strain (LVGCS) and radial strain (LVGRS) are echocardiographic parameters with wide clinical applicability. However, the thresholds for abnormal left ventricular (LV) strains, particularly the lower limits of normal (LLN), are not well established. This meta-analysis determined the mean and LLN of two- (2D) and three-dimensional (3D) LV strain in healthy subjects and factors that influence strain measurements.

Methods

We searched PubMed, Embase and Cochrane databases until 31 December 2019 for studies reporting left ventricular (LV) global strain in at least 50 healthy subjects. We pooled means and LLNs of 2D and 3D LV strain using random-effects models, and performed subgroup and meta-regression analysis for LVGLS.

Results

Forty-four studies were eligible totaling 8,910 subjects. The pooled means and LLNs (95% confidence intervals) were -20.1% (-20.7%, -19.6%) and -15.4% (-16.0%, -14.7%) respectively for 2D-LVGLS; -21.9% (-23.4%, -20.3%) and -15.3% (-16.9%, -13.8%) respectively for 2D-LVGCS; and 48.4% (43.8%, 53.0%) and 25.5% (17.8%, 33.1%) respectively for 2D-LVGRS. All pooled analyses demonstrated significant heterogeneity, and means and LLNs of and 3D-LV strains differed marginally from 2D. Only vendor software was associated with differences in pooled means and LLN of 2D-LVGLS.

Conclusions

In conclusion, pooled means and LLNs of 2D- and 3D-LV global strain parameters in healthy subjects were reported. Based on the pooled LLNs, thresholds for abnormal, borderline and normal strains can be defined, such as less negative than -14.7%, between -14.7% and -16.0% and more negative than -16.0% respectively for 2D-LVGLS, and 2D-LVGLS values are only affected by vendor software.

Abstract 13434: Improved Diagnostic Performance of Contemporary Transesophageal Echocardiography With Three-dimensional Imaging for Infective Endocarditis

Introduction: Infective endocarditis (IE) is associated with high morbidity and mortality. Conventionally, a repeat transesophageal echocardiogram (TEE) is necessary if the first TEE is negative, and there is high clinical suspicion. We aimed to investigate the diagnostic performance of contemporary TEE for IE.

Hypothesis: We hypothesize that with advancements in TEE imaging, including three-dimensional (3D) imaging, the diagnostic performance of TEE for IE would be improved.

Methods: Patients who had two or more TEEs at our center, within 6 months, for evaluation of IE in 2011 (pre-3D imaging) and 2019 (post-3D imaging) were included. Patients not meeting the Duke criteria for IE (n=899) were excluded. The primary endpoint was the sensitivity of TEE to detect IE. TEE sensitivity was also compared among the different subtypes of IE (native valve, prosthetic valve, device-related, central line-related, and aortic prosthetic graft-related).

Results: 242 patients were included: 70 in 2011 and 172 in 2019. In 2011, there were more smokers and a lower rate of pacing devices; otherwise, there were no significant differences in baseline characteristics, including intravenous drug use. The sensitivity of the initial TEE for IE was 85.7% in 2011, improving significantly to 95.3% in 2019 (p=0.01). The improved diagnostic performance in 2019 was mainly driven by the improved detection of prosthetic valve IE (70.8% vs. 93.7%, p=0.009). There were no significant differences for the other subtypes of IE (Figure). In 2019, patients had a higher rate of IE diagnosis within 15 days of index admission, which did not reach statistical significance (n=161, 93.6% vs. n=62, 88.6% in 2011, p=0.19). Kaplan Meier analysis demonstrated that patients in 2019 had a higher rate of procedures for endocarditis (p=0.01).

Conclusions: Contemporary TEE imaging including 3D technology improved the detection of IE on the initial TEE, mainly driven by improved detection of prosthetic valve IE.

Complementary Diagnostic and Prognostic Contributions of Cardiac Computed Tomography for Infective Endocarditis Surgery

BACKGROUND

Cardiac computed tomography (CT) is emerging as an adjunctive modality to echocardiography in the evaluation of infective endocarditis (IE) and surgical planning. CT studies in IE have, however, focused on its diagnostic rather than prognostic utility, the latter of which is important in high-risk diseases like IE. We evaluated the associations between cardiac CT and transesophageal echocardiography (TEE) findings and adverse outcomes after IE surgery.

METHODS

Of 833 consecutive patients with surgically proven IE during May 1, 2014 to May 1, 2019, at Cleveland Clinic, 155 underwent both preoperative ECG-gated contrast-enhanced CT and TEE. Multivariable analyses were performed to identify CT and TEE biomarkers that predict adverse outcomes after IE surgery, adjusting for EuroSCORE II (European System for Cardiac operative Risk Evaluation II).

RESULTS

CT and TEE were positive for IE in 123 (75.0%) and 124 (75.6%) of patients, respectively. Thirty-day mortality occurred in 3 (1.9%) patients and composite mortality or morbidities in 72 (46.5%). Pseudoaneurysm or abscess detected on TEE was the only imaging biomarker to show independent association with composite mortality or morbidities in-hospital, with odds ratio (95% CI) of 3.66 (1.76-7.59), P=0.001. There were 17 late deaths, and both pseudoaneurysm or abscess detected on CT and fistula detected on CT were the only independent predictors of total mortality during follow-up, with hazards ratios (95% CI) of 3.82 (1.25-11.7), P<0.001 and 9.84 (1.89-51.0), P=0.007, respectively.

CONCLUSIONS

We identified cardiac CT and TEE features that predicted separate adverse outcomes after IE surgery. Imaging biomarkers can play important roles incremental to conventional clinical factors for risk stratification in patients undergoing IE surgery.

Contemporary Outcomes in Low-Gradient Aortic Stenosis Patients Who Underwent Dobutamine Stress Echocardiography

Background

Detection of flow reserve (FR) by dobutamine stress echocardiography is used for risk stratification in low‐gradient aortic stenosis (AS). Prognostic significance of dobutamine stress echocardiography in the transcatheter aortic valve replacement era is unclear. We aimed to assess the current relevance of FR.

Methods and Results

We studied 235 patients with low‐gradient severe AS (rest aortic valve area ≤1.0 cm² or indexed aortic valve area ≤0.60 cm²/m²; mean aortic valve gradient <40 mm Hg) and left ventricular ejection fraction <50%) with dobutamine stress echocardiography done September 2010 through July 2016. FR was defined by ≥20% stroke volume increase. We diagnosed “true‐severe AS” if peak aortic valve velocity ≥4 m/s occurred with aortic valve area ≤1.0 cm² (or indexed aortic valve area ≤0.6 cm²/m²). At a median time of 51 days, 128 patients underwent aortic valve replacement,either surgical aortic valve replacement (n=42) or transcatheter aortic valve replacement (n=86). FR was observed in 138 patients, while 86 patients had true‐severe AS. During median follow‐up of 2.3 years, 138 patients died. In a multivariable model, aortic valve replacement (hazard ratio 0.41, 95% CI: 0.29–0.58, P <0.001) and lower Society of Thoracic Surgeons score (hazard ratio 1.06, 95% CI: 1.04–1.09, P<0.001) were associated with better survival, while FR was not predictive. aortic valve replacement was associated with survival regardless of the presence or absence of FR or AS severity stratification.

Conclusions

In low‐gradient AS with reduced ejection fraction, FR or AS severity stratification by dobutamine stress echocardiography was not associated with survival. Aortic valve replacement was associated with better survival in low‐gradient AS independent of FR.

See Editorial by Annabi et al

Machine Learning of 12-Lead QRS Waveforms to Identify Cardiac Resynchronization Therapy Patients With Differential Outcomes

BACKGROUND

Cardiac resynchronization therapy (CRT) improves heart failure outcomes but has significant nonresponse rates, highlighting limitations in ECG selection criteria: QRS duration (QRSd) ≥150 ms and subjective labeling of left bundle branch block (LBBB). We explored unsupervised machine learning of ECG waveforms to identify CRT subgroups that may differentiate outcomes beyond QRSd and LBBB.

METHODS

We retrospectively analyzed 946 CRT patients with conduction delay. Principal component analysis (PCA) dimensionality reduction obtained a 2-dimensional representation of preCRT 12-lead QRS waveforms. k-means clustering of the 2-dimensional PCA representation of 12-lead QRS waveforms identified 2 patient subgroups (QRS PCA groups). Vectorcardiographic QRS area was also calculated. We examined following 2 primary outcomes: (1) composite end point of death, left ventricular assist device, or heart transplant, and (2) degree of echocardiographic left ventricular ejection fraction (LVEF) change after CRT.

RESULTS

Compared with QRS PCA Group 2 (n=425), Group 1 (n=521) had lower risk for reaching the composite end point (HR, 0.44 [95% CI, 0.38-0.53]; P<0.001) and experienced greater mean LVEF improvement (11.1±11.7% versus 4.8±9.7%; P<0.001), even among patients with LBBB with QRSd ≥150 ms (HR, 0.42 [95% CI, 0.30-0.57]; P<0.001; mean LVEF change 12.5±11.8% versus 7.3±8.1%; P=0.001). QRS area also stratified outcomes but had significant differences from QRS PCA groups. A stratification scheme combining QRS area and QRS PCA group identified patients with LBBB with similar outcomes to non-LBBB patients (HR, 1.32 [95% CI, 0.93-1.62]; difference in mean LVEF change: 0.8% [95% CI, -2.1% to 3.7%]). The stratification scheme also identified patients with LBBB with QRSd <150 ms with comparable outcomes to patients with LBBB with QRSd ≥150 ms (HR, 0.93 [95% CI, 0.67-1.29]; difference in mean LVEF change: -0.2% [95% CI, -2.7% to 3.0%]).

CONCLUSIONS

Unsupervised machine learning of ECG waveforms identified CRT subgroups with relevance beyond LBBB and QRSd. This method may assist in objective classification of bundle branch block morphology in CRT.

The role of cardiac imaging in hospitalized COVID-19-positive patients

COVID-19 infection is associated with several cardiac complications with high rates of adverse outcomes. Cardiac imaging has different utility in different clinical scenarios, and the importance of minimizing healthcare worker exposure should be considered. Cardiac imaging should only be ordered if its benefits outweigh its risks, with anticipated changes in acute treatment and outcomes, and no suitable alternative of sufficient adequacy is available. Indications for advanced cardiac imaging for COVID-19 patients in the acute phase are limited, although follow-up imaging in the convalescent stage may provide prognostic importance in recovered COVID-19 patients with positive troponin or decompensated heart failure.

Long-Term Outcomes in Patients With Mixed Aortic Valve Disease and Preserved Left Ventricular Ejection Fraction

Background

Concurrent presence of aortic stenosis and aortic regurgitation is termed mixed aortic valve disease (MAVD). Although multiple articles have addressed patients with “isolated” aortic stenosis or aortic regurgitation, the natural history, impact, and outcomes of MAVD are not well defined. Here, we evaluate long‐term outcomes in patients with MAVD and cardiovascular adaptations to chronic MAVD.

Methods and Results

This observational cohort study evaluated 862 adult patients (56.8% male) with preserved left ventricular ejection fraction and at least moderate aortic regurgitation and moderate aortic stenosis. Primary outcome was all‐cause mortality. Subgroup analysis was based on treatment modality (aortic valve replacement [AVR] versus medical management). A regression analysis of longitudinal echocardiographic parameters was performed to assess the natural history of MAVD. Mean age was 68±15 years, and mean left ventricular ejection fraction was 58±5%. At 4.6 years (25th–75th percentile range, 1.0–8.7), 58.6% of patients underwent an AVR and 48.8% patients died. In both unadjusted and adjusted Cox survival analysis, AVR was associated with improved survival (hazard ratio, 0.41; 95% CI, 0.34–0.51, P<0.001). Impact of AVR persisted when stratifying the cohort by symptom status and baseline aortic valve area (log rank, P<0.001 for both) and after propensity‐score matching (hazard ratio, 0.40; 95% CI, 0.32–0.50; P<0.001). In the longitudinal analysis, there were statistically significant changes over time in aortic valve peak gradient (P<0.001) and aortic valve area (P<0.001) and only mild increases in left ventricular end‐diastolic (P<0.007) and ‐systolic (P<0.001) volumes.

Conclusions

MAVD confers a high risk of all‐cause mortality. However, AVR significantly reduces this risk independent of aortic valve area, symptom status, and after controlling for confounding variables.

Machine Learning Prediction of Response to Cardiac Resynchronization Therapy: Improvement Versus Current Guidelines

BACKGROUND

Cardiac resynchronization therapy (CRT) has significant nonresponse rates. We assessed whether machine learning (ML) could predict CRT response beyond current guidelines.

METHODS

We analyzed CRT patients from Cleveland Clinic and Johns Hopkins. A training cohort was created from all Johns Hopkins patients and an equal number of randomly sampled Cleveland Clinic patients. All remaining patients comprised the testing cohort. Response was defined as ≥10% increase in left ventricular ejection fraction. ML models were developed to predict CRT response using different combinations of classification algorithms and clinical variable sets on the training cohort. The model with the highest area under the curve was evaluated on the testing cohort. Probability of response was used to predict survival free from a composite end point of death, heart transplant, or placement of left ventricular assist device. Predictions were compared with current guidelines.

RESULTS

Nine hundred twenty-five patients were included. On the training cohort (n=470: 235, Johns Hopkins; 235, Cleveland Clinic), the best ML model was a naive Bayes classifier including 9 variables (QRS morphology, QRS duration, New York Heart Association classification, left ventricular ejection fraction and end-diastolic diameter, sex, ischemic cardiomyopathy, atrial fibrillation, and epicardial left ventricular lead). On the testing cohort (n=455, Cleveland Clinic), ML demonstrated better response prediction than guidelines (area under the curve, 0.70 versus 0.65; P=0.012) and greater discrimination of event-free survival (concordance index, 0.61 versus 0.56; P<0.001). The fourth quartile of the ML model had the greatest risk of reaching the composite end point, whereas the first quartile had the least (hazard ratio, 0.34; P<0.001).

CONCLUSIONS

ML with 9 variables incrementally improved prediction of echocardiographic CRT response and survival beyond guidelines. Performance was not improved by incorporating more variables. The model offers potential for improved shared decision-making in CRT (online calculator: http://riskcalc.org:3838/CRTResponseScore ). Significant remaining limitations confirm the need to identify better variables to predict CRT response.

Characteristics and Outcomes in a Contemporary Group of Patients With Suspected Significant Mitral Stenosis Undergoing Treadmill Stress Echocardiography

Background:

In contemporary patients with suspected significant mitral stenosis (MS) undergoing rest and treadmill stress echocardiography, we assessed characteristics and factors associated with longer-term survival.

Methods:

We studied 515 consecutive patients (asymptomatic/atypical symptoms, mean left ventricular ejection fraction 58±2%; 43% male) with suspected at least moderate MS ([1] native mitral valve [MV]: resting mean MV gradient ≥5 mm Hg or area ≤1.5 cm 2 and [2] prosthetic valve: resting mean MV gradient ≥5 mm Hg or effective orifice area ≤2 cm) who underwent rest and treadmill stress echocardiography between 1/2003 and 12/2013. MS was categorized as rheumatic (n=170, 33%), postsurgical (prior mitral repair/replacement, n=245, 48%), and primary nonrheumatic (n=100, 19%). Primary outcome was all-cause mortality.

Results:

Mean resting MV gradient and right ventricular systolic pressure were 8.5±3 and 39±13 mm Hg. Patients achieved 95±29% age-sex predicted metabolic equivalents; peak-stress MV gradient and right ventricular systolic pressure were 17±7 and 61±14 mm Hg, respectively. At 54 days (median), 224 (44%) underwent invasive mitral procedure. At 6±4 years, 76 (15%) died. On survival analysis, primary nonrheumatic MS (hazard ratio [HR], 4.92), higher Society of Thoracic Surgeons score (HR, 1.92), lower % age-sex predicted metabolic equivalents (HR, 1.22), and higher peak-stress right ventricular systolic pressure (HR, 1.35), was associated with higher mortality, while invasive mitral procedures were associated with improved survival (HR, 0.67; all P <0.01).

Conclusions:

In asymptomatic patients (or with atypical symptoms) with significant MS undergoing treadmill stress echocardiography, higher mortality was associated with primary nonrheumatic MS, lower % age-sex predicted metabolic equivalents, and higher peak-stress right ventricular systolic pressure, while invasive MV procedures were associated with survival.

Teamwork using strain imaging in the echocardiographic assessment of right ventricular systolic function: A cardiac magnetic resonance imaging correlation study

AIM

The aim of this study was to investigate whether conventional echocardiographic assessment of right ventricular (RV) systolic function can be improved by the addition of RV strain imaging. Additionally, we also aimed to investigate whether dedicated reading sessions and education can improve echocardiographic interpretation of RV systolic function.

METHODS

Readers of varying expertise (staff echocardiologists, advanced cardiovascular imaging fellows, sonographers) assessed RV systolic function. In session 1, 20 readers graded RV function of 19 cases, using conventional measures. After dedicated education, in session 2, the same cases were reassessed, with the addition of RV strains. In session 3, 18 readers graded RV function of 20 additional cases, incorporating RV strains. Computer simulations were performed to obtain 230 random teams. RV ejection fraction (RVEF) by cardiac magnetic resonance (CMR) was the reference standard.

RESULTS

Correlation between RV GLS and CMR-derived RVEF was moderate: Spearman's rho: 0.70, n = 19, P < 0.001 (first two sessions); 0.55, n = 20, P < 0.05 (third session). Individual readers' assessment moderately correlated with RVEF (Spearman's rho first session: 0.67 ± 0.2; second session: 0.61 ± 0.2; and third session: 0.68 ± 0.09). Team estimates of RV systolic function showed consistently better correlation with RVEF, which were improved further by averaging across all readers. RV strain parameters influenced echocardiographic interpretation, with a net reclassification index of 8.0 ± 3.6% (P = 0.014).

CONCLUSIONS

The RV strain parameters showed moderate correlations with CMR-derived RVEF and appropriately influenced echocardiographic interpretation of RV systolic function. "Wisdom of the crowd" applied by averaging echocardiographic assessments of RV systolic function across teams of echocardiography readers, further improved echocardiographic assessment of RV systolic function.

Impact of abnormal longitudinal rotation on the assessment of right ventricular systolic function in patients with severe pulmonary hypertension

Background

Assessment of right ventricular (RV) function plays an important role in patients with cardiopulmonary disease, and current guidelines recommend parameters including tricuspid annular plane systolic excursion (TAPSE) and right ventricular systolic excursion velocity (RVS') to assess RV longitudinal function. We assessed the hypothesis that the previously undescribed motion of RV longitudinal rotation (RVLR) is an independent predictor of both TAPSE and RVS'.

Methods

We assessed a series of 100 consecutive patients with pulmonary hypertension (PH) undergoing echocardiography. Patients with left ventricular (LV) dilation and dysfunction were excluded. Standard RV parameters were determined using established guidelines, while RVLR and right ventricular global longitudinal strain (RVGLS) measurements were performed using 2-dimensional (2D) speckle tracking technique.

Results

Mean peak RVLR measured -4.2±3.7 degrees. By convention, negative values implied clockwise motion. In a multiple linear regression model, TAPSE could be predicted from a combination of RVLR and RVGLS (R=0.56, P<0.001). A similar relationship was found for RVS' which could also be predicted from a combination of RVLR and RVGLS (R=0.52, P<0.001). While no association was found between RVLR and RV size, estimated RV systolic pressure (RVSP) or the presence of a pericardial effusion, a mild correlation was noted between RVLR and QRS duration (R=0.25, P=0.01).

Conclusions

RVLR is an independent predictor of TAPSE and RVS'. Awareness of this motion should be considered in the interpretation of TAPSE and RVS' values as markers of RV systolic function, as abnormal RVLR may account for exaggerated values, particularly in patients with PH and RV dysfunction.

Exercise capacity in asymptomatic patients with significant primary mitral regurgitation: independent effect of global longitudinal left ventricular strain

Background

Despite preserved left ventricular ejection fraction (LVEF), patients with significant primary mitral regurgitation (MR) often have reduced exercise capacity. In asymptomatic patients with ≥3+ primary MR undergoing rest-stress echocardiography (RSE), we sought to evaluate the incremental impact of left ventricular global longitudinal strain (LV-GLS) on exercise capacity.

Methods

A total of 660 asymptomatic patients with ≥3+ primary MR, non-dilated LV and LVEF ≥60% (mean age, 57±14 years, 66% men, body mass index or BMI 25±4 kg/m²) who underwent RSE at our center between 2001 and 2013 were included. Standard RSE data were obtained. Average resting LV-GLS was measured using Velocity Vector Imaging.

Results

Mean mitral effective regurgitant orifice, resting right ventricular systolic pressure (RVSP) and LV-GLS were 0.45±0.2 cm², 31±12 mmHg and -21.7%±2%, respectively; 28% had flail mitral leaflet. Mean metabolic equivalents (METs) and post-stress RVSP were 9.9±3, and 46±15 mmHg; 28% achieved <100% age-gender predicted METs. No patient had ischemia or significant arrhythmias. On logistic regression, resting LV-GLS [odds ratio (OR), 1.40, 95% confidence interval (CI): 1.21-1.55, BMI (OR, 1.11, 95% CI: 1.06-1.17)] and resting RVSP 1.22 (1.02-1.49) were independent predictors of exercise capacity. Area under the curve for association between 100% age-gender predicted METs and various factors were as follows: (I) BMI (0.60, 95% CI: 0.55-0.65, P<0.001); (II) resting RVSP (0.57, 95% CI: 0.52-0.62, P=0.006) and LV-GLS (0.66, 95% CI: 0.61-0.70, P<0.001).

Conclusions

In asymptomatic patients with ≥3+ primary MR, non-dilated LV and preserved LVEF, LV-GLS is independently associated with exercise capacity, beyond known predictors.