Optimal Technique for Measurement of Linear Left Ventricular Dimensions

Accuracy of Devereaux and Teichholz formulas for left ventricular mass calculation in different geometric patterns: comparison with cardiac magnetic resonance imaging

Left ventricular (LV) myocardial mass is important in the evaluation of cardiac remodeling and requires accurate assessment when performed on linear measurements in two-dimensional echocardiography (Echo). We aimed to compare the accuracy of the Devereaux formula (DEV) and the Teichholz formula (TEICH) in calculating LV myocardial mass in Echo using cardiac magnetic resonance (CMR) as the reference method. Based on preceding mathematical calculations, we identified primarily LV size rather than wall thickness as the main source of bias between DEV and TEICH in a retrospective derivation cohort (n = 1276). Although LV mass from DEV and TEICH were correlated with CMR, TEICH did not show a proportional bias as did DEV (- 2 g/m2 vs. + 22 g/m2). This could be validated in an independent prospective cohort (n = 226) with symptomatic non-ischemic heart failure. DEV systematically overestimated LV mass in all tiers of LV remodeling as compared to TEICH. In conclusion, the TEICH method accounts for the changes in LV geometry with increasing LV mass and thus better reflects the different pattern of LV remodeling than the DEV method. This has important clinical implications, as TEICH may be more appropriate for use in clinical practice, rather than DEV, currently recommended.

Ultrasound Enhancing Agents with Transthoracic Echocardiography for Maximal Wall Thickness in Hypertrophic Cardiomyopathy

Objectives

To determine whether ultrasound enhancing agent (UEA) changes maximal wall thickness (WT) in hypertrophic cardiomyopathy (HCM), and if it improves correlation with magnetic resonance imaging (MRI).

Patients and Methods

A total of 107 patients with HCM were prospectively enrolled at a single tertiary referral center between July 10, 2014, and August 31, 2017, and underwent transthoracic echocardiography (TTE) with and without UEA and MRI. Maximal WT measurements were compared, and variability among the 3 modalities was evaluated using a simple linear regression analysis and paired t tests and Bland-Altman plots. Interobserver variability for each technique was assessed.

Results

Most (63%) of cardiac imagers found UEA helpful in determining maximal WT by TTE, with 49% reporting change in WT. Of 52 patients where UEA changed WT measurement, 32 (62%) reported an increase and 20 (38%) reported a decrease in WT. The UEA did not alter the median discrepancy in WT between MRI and TTE. However, where UEA increased reported WT, the difference between MRI and TTE improved in 79% of cases (P=.001) from 2.0-0.5mm. In those with scar on MRI, UEA improved agreement of WT between TTE and MRI compared with that of TTE without UEA (79% vs 39%; P=.011). Interclass correlation coefficient for WT for TTE without UEA, with UEA, and MRI was 0.84; (95% CI, 0.61-0.92), 0.88; (95%CI, 0.82-0.92), and 0.97; (95%CI, 0.96-0.98), respectively.

Conclusion

Although use of UEA did not eliminate differences in WT discrepancy between modalities, the addition of UEA to TTE aided in WT determination and improved correlation with MRI in those with greater WT and in all patients with myocardial scars.

Association of Left Ventricular Remodeling Assessment by Cardiac Magnetic Resonance With Outcomes in Patients With Chronic Aortic Regurgitation

Importance

Chronic aortic regurgitation (AR) causes left ventricular (LV) volume overload, which results in progressive LV remodeling negatively affecting outcomes. Whether cardiac magnetic resonance (CMR) volumetric quantification can provide incremental risk stratification over standard clinical and echocardiographic evaluation in patients with chronic moderate or severe AR is unknown.

Objective

To compare LV remodeling measurements by CMR and echocardiography between patients with and without heart failure symptoms and to verify the association of remodeling measurements of patients with chronic moderate or severe AR but no or minimal symptoms with clinical outcomes receiving medical management.

Design, Setting, and Participants

This multicenter retrospective cohort study included consecutive patients with at least moderate chronic native AR evaluated by 2-dimensional transthoracic echocardiography and CMR examination within 90 days from each other between January 2012 and February 2020 at Allina Health System. Data were analyzed from June 2021 to January 2022.

Exposures

Clinical evaluation and risk stratification by CMR.

Main Outcomes and Measures

The end point was a composite of death, heart failure hospitalization, or progression of New York Heart Association functional class while receiving medical management, censoring patients at the time of aortic valve replacement (when performed) or at the end of follow-up.

Results

Of the 178 included patients, 119 (66.9%) were male, 158 (88.8%) presented with no or minimal symptoms (New York Heart Association class I or II), and the median (IQR) age was 58 (44-69) years. Compared with patients with no or minimal symptoms, symptomatic patients had greater LV end-systolic volume index (LVESVi) by CMR (median [IQR], 66 [46-85] mL/m2 vs 42 [30-58] mL/m2; P < .001), while there were no significant differences by echocardiography (LVESVi: median [IQR], 38 [30-58] mL/m2 vs 27 [20-42] mL/m2; P = .07; LV end-systolic diameter index: median [IQR], 21 [17-25] mm/m2 vs 18 [15-22] mm/m2; P = .17). During the median (IQR) follow-up of 3.3 (1.6-5.8) years, 50 patients with no or minimal symptoms receiving medical management developed the composite end point, which, in multivariate analysis adjusted for age and EuroSCORE II, was independently associated with LVESVi of 45 mL/m2 or greater and aortic regurgitant fraction of 32% or greater, the latter adding incremental prognostic value to CMR volumetric assessment.

Conclusions and Relevance

In patients with chronic moderate or severe AR, patients presenting with heart failure symptoms have greater LVESVi by CMR than those with no or minimal symptoms. In patients with no or minimal symptoms, CMR quantification of LVESVi and AR severity may identify those at risk of death or incident heart failure and therefore should be considered in the clinical evaluation and decision-making of these patients.

A new method to quantify left ventricular mass by 2D echocardiography

Increased left ventricular mass (LVM) is a strong independent predictor for adverse cardiovascular events, but conventional echocardiographic methods are limited by poor reproducibility and accuracy. We developed a novel method based on adding the mean wall thickness from the parasternal short axis view, to the left ventricular end-diastolic volume acquired using the biplane model of discs. The participants (n = 85) had various left ventricular geometries and were assessed using echocardiography followed immediately by cardiac magnetic resonance, as reference. We compared our novel two-dimensional (2D) method to various conventional one-dimensional (1D) and other 2D methods as well as the three-dimensional (3D) method. Our novel method had better reproducibility in intra-examiner [coefficients of variation (CV) 9% vs. 11–14%] and inter-examiner analysis (CV 9% vs. 10–20%). Accuracy was similar to the 3D method (mean difference ± 95% limits of agreement, CV): Novel: 2 ± 50 g, 15% vs. 3D: 2 ± 51 g, 16%; and better than the “linear” 1D method by Devereux (7 ± 76 g, 23%). Our novel method is simple, has considerable better reproducibility and accuracy than conventional “linear” 1D methods, and similar accuracy as the 3D-method. As the biplane model forms part of the standard echocardiographic protocol, it does not require specific training and provides a supplement to the modern echocardiographic report.

Association of Left Ventricular Volume in Predicting Clinical Outcomes in Patients with Aortic Regurgitation

BACKGROUND

Aortic regurgitation (AR) is a common valvular lesion associated with increased mortality once the left ventricle enlarges significantly or develops systolic dysfunction (ejection fraction < 50%). Valve guidelines recommend aortic valve repair or replacement (AVR) for left ventricular (LV) linear end-systolic dimension ≥ 50 mm or end-diastolic dimension ≥ 65 mm. However, chamber quantification guidelines recommend using LV volume for LV size determination because linear measurements may not accurately reflect LV remodeling. The aim of this study was to evaluate the correlation of LV volumes with linear dimensions, interobserver variability in the estimation of volumes, and the association of volumes with outcomes in patients with AR.

METHODS

A total of 1,100 consecutive patients with chronic moderate to severe and severe AR on echocardiography between 2004 and 2019 were retrospectively analyzed. The modified Simpson disk summation method was used for LV volume estimation. The primary outcome was all-cause mortality; the secondary outcome was mortality censored at AVR.

RESULTS

Patients' age was 60 ± 17 years, and 198 were women (18%). Volumes were measured using the biplane method in 939 patients (85%) and the monoplane method in 161 (15%); end-systolic volume was normal in 169 (11%). Correlations between volumes and linear dimensions were 0.5 for end-diastolic volume and 0.6 for end-systolic volume. At median follow-up of 5.4 years (interquartile range, 2.4-10.0 years), 216 patients had died and 539 had undergone AVR. Indexed LV end-systolic volume (iLVESV) and indexed left ventricular end-systolic dimension were both associated with mortality and symptoms, but the association of iLVESV was stronger. iLVESV, age, male gender, Charlson comorbidity index, New York Heart Association functional class III or IV, and time-dependent AVR were independently associated with all-cause mortality. Interobserver variability in the estimation of LV volumes in 200 patients included intraclass coefficients of 0.94 (95% CI, 0.92-0.95) for end-diastolic volume and 0.88 (95% CI, 0.78-0.93) for end-systolic volume. Patients with iLVESV ≥ 45 mL/m² had lower survival and a higher prevalence of symptoms than those with volumes < 45 mL/m².

CONCLUSIONS

Echocardiographic LV volume assessment had good reproducibility in patients with moderate to severe and severe AR. The correlation between linear dimensions and volumes was limited. Both iLVESV and indexed left ventricular end-systolic dimension were associated with worse outcomes, but the association of iLVESV was stronger. iLVESV ≥ 45 mL/m² was associated with worse outcomes.

Paradoxical low-flow phenotype in hospitalized heart failure with preserved ejection fraction

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Patients with HFpEF and paradoxical low forward flow have a worse outcome.

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Stroke volume index identifies HFpEF patients with paradoxical low flow.

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Small LV cavity, atrial fibrillation and RV dysfunction affect paradoxical low flow.

Background

Low flow (LF) in heart failure with preserved ejection fraction (HFpEF) is a paradox but is associated with worse prognosis. Determinants of LF in HFpEF have not been clarified but their assessment could corroborate recognition and definition of such a paradoxical condition.

Methods

A cohort of 193 patients hospitalized with HFpEF was retrospectively studied and divided in a group with LF (N = 45), defined by a left ventricular (LV) stroke volume index (SVI) < 30 ml/m², and a group with normal flow (N = 148). A small LV cavity was pre-defined as LV end diastolic diameter index (EDDI) below median values (<25 mm/m² for males and <26 mm/m² for females). Right ventricular dysfunction (RVD) was defined as the ratio between tricuspid annular plane systolic excursion and systolic pulmonary artery pressure < 0.36 mm/mmHg. An endpoint of all-cause mortality was evaluated after a median follow-up of 2.4 years.

Results

RVD (OR = 7.4; P < 0.001), atrial fibrillation (AF) during echocardiography (OR = 3.26; P = 0.008), and small LV cavity (OR = 3.81; P = 0.003) were independently associated with LF. After adjusting for age, body mass index, systolic blood pressure, renal function, chronic obstructed pulmonary disease, use of ACE inhibitors/angiotensin receptor blockers, moderate tricuspid regurgitation, RVD), LF was associated with mortality (HR = 3.69; P < 0.001) whereas the combination of the determinants of LF was not.

Conclusion

Paradoxical LF in HFpEF is associated with small LV cavity, AF and RVD. None of the combination of different factors associated with LF could substitute direct assessment of LF status in predicting prognosis in this cohort.

Gender differences among ischemic heart disease patients enrolled in a cardiac rehabilitation program

BACKGROUND

Cardiac rehabilitation programs reduce cardiovascular events and mortality in ischemic heart disease patients. The aim of this study was to assess gender differences among ischemic heart disease patients enrolled in a cardiac rehabilitation program regarding adherence to the program, as well as, changes in clinical, laboratory, and echocardiographic parameters.

RESULTS

A prospective study that included 30 men and 30 women with stable ischemic heart disease who had been totally revascularized by percutaneous coronary intervention. Patients were enrolled in a 12-week cardiac rehabilitation program. Assessment of demographics, anthropometric measurements, risk factors, and functional capacity was performed. Lipid profile, glycated hemoglobin, and left ventricular ejection fraction were assessed. Assessments were performed at baseline and after completion of the program. Time to enrollment in the program was prolonged for women 39.17 ± 40.49 vs. 19.77 ± 10.26 days (p = 0.014). At baseline, more women were diabetic (p = 0.004), hypertensive (p = 0.02), had a larger waist circumference (p = 0.022), a higher BMI (p = 0.011), and higher HbA1c (p = 0.033). More men were active smokers (p < 0.001). After completion of the program, it was found that men attended 19.1 ± 4.77 (79.6%) sessions compared to 15.7 ± 5.72 (65.4%) sessions for women (p = 0.015). Women had more reduction in diastolic BP - 10.93 ± 8.94 vs. - 5.47 ± 12.57 mmHg (p = 0.058). The magnitude of reduction in resting heart rate was significant in men (p = 0.018) but not in women (p = 0.376). The magnitude of reduction in serum total cholesterol and triglycerides was more in men (p = 0.018 and p = 0.014). Women showed more reduction in HbA1c (p = 0.052).

CONCLUSION

Men are more adherent to cardiac rehabilitation programs. Recruitment of women is significantly delayed. Women have a higher cardiovascular risk burden in the form of prevalence of diabetes, hypertension, and obesity. Completion of a cardiac rehabilitation program causes a reduction in BMI, waist circumference, blood pressure measurements, total cholesterol, triglycerides, LDL-C, HDL-C, HbA1c, and LVEDD with an increase in LVEF in both genders. Men show more reduction in resting HR, total cholesterol, and triglyceride levels while women show more reduction in diastolic BP and HBA1c.