New classification of geometric ventricular patterns in severe aortic stenosis: Could it be clinically useful?

Effects of Hypertrophic and Dilated Cardiac Geometric Remodeling on Ejection Fraction

Background: Both heart failure (HF) with preserved ejection fraction (HFpEF) and heart failure with reduced ejection fraction (HFrEF) can present a wide variety of cardiac morphologies consequent to cardiac remodeling. We sought to study if geometric changes to the heart during such remodeling will adversely affect the ejection fraction (EF) parameter’s ability to serve as an indicator of heart function, and to identify the mechanism for it.

Methods and Results: A numerical model that simulated the conversion of myocardial strain to stroke volume was developed from two porcine animal models of heart failure. Hypertrophic wall thickening was found to elevate EF, while left ventricle (LV) dilation was found to depress EF when myocardial strain was kept constant, causing EF to inaccurately represent the overall strain function. This was caused by EF being calculated using the endocardial boundary rather than the mid-wall layer. Radial displacement of the endocardial boundary resulted in endocardial strain deviating from the overall LV strain, and this deviation varied with LV geometric changes. This suggested that using the epi- or endo-boundaries to calculate functional parameters was not effective, and explained why EF could be adversely affected by geometric changes. Further, when EF was modified by calculating it at the mid-wall layer instead of at the endocardium, this shortcoming was resolved, and the mid-wall EF could differentiate between healthy and HFpEF subjects in our animal models, while the traditional EF could not.

Conclusion: We presented the mechanism to explain why EF can no longer effectively indicate cardiac function during cardiac geometric changes relevant to HF remodeling, losing the ability to distinguish between hypertrophic diseased hearts from healthy hearts. Measuring EF at the mid-wall location rather than endocardium can avoid the shortcoming and better represent the cardiac strain function.

Valvular Heart Disease Epidemiology

Valvular heart disease is a rapidly growing cause of global cardiovascular morbidity and mortality with diverse and evolving geographic distribution. The prevalence of rheumatic heart disease, the most common valvular heart disease (affecting approximately 41 million people), has been rising in developing nations, likely due to the expansion of the young adult population and the decrease in premature mortality that has resulted from improved access to antibiotics, microbiological testing, and echocardiography. Rheumatic heart disease has also been rising among the impoverished and, often, indigenous populations of developed nations, spurring public health initiatives that are aimed at alleviating healthcare disparities. Aortic valve stenotic disease is the most commonly occurring valvular pathology in developed nations (afflicting 9 million people worldwide) and its prevalence has been increasing with population aging and the increased prevalence of atherosclerosis. Aortic regurgitation is associated with diastolic, but not systolic, hypertension and it has likewise seen a rise in the developed world. Mitral regurgitation affects 24 million people worldwide, with great variability between and among nations. Primary mitral regurgitation arises as a consequence of myxomatous degeneration and mitral valve prolapse, which is largely due to genetic predispositions, while secondary mitral regurgitation accounts for 65% of cases and arises secondary to dilation and heart failure. Tricuspid regurgitation has become more prevalent in developed nations due to the increased usage of intracardiac pacemakers. Infective endocarditis prevalence has also grown in developed nations, likely due to population aging and the increased utilization of transcatheter valve replacement and prosthetic valves as interventions against the previously discussed valvular pathologies.

Predictors of Mortality Following Aortic Valve Replacement in Aortic Stenosis Patients

Background: Understanding of the risk factors for the development of adverse outcomes after aortic valve replacement is necessary to develop timely preventive measures and to improve the results of surgical treatment. Methods: We analyzed patients with aortic stenosis (n = 742) who underwent surgical treatment in the period 2014−2020. The average age was 63 (57;69) years—men 58%, women 42%. Results: The hospital mortality rate was 3% (22 patients). The following statistically significant threshold values (cut-off points) were obtained in the ROC analysis: aortic cross-clamp time > 93 min AUC (CI) 0.676 (0.640−0.710), p = 0.010; cardiopulmonary bypass time > 144 min AUC (CI) 0.809 (0.778−0.837), p < 0.0001, hemoglobin before op <120 g/L. AUC (CI) 0.762 (0.728−0.793), p < 0.0001, hematocrit before op <39% AUC (CI) 0.755 (0.721−0.786), p < 0.001, end-diastolic dimension index >2.39 AUC (CI) 0.647 (0.607−0.686), p = 0.014, end-systolic dimension index > 1.68 AUC (CI) 0.657 (0.617−0.695), p = 0.009. Statistically significant independent predictors of hospital mortality were identified: BMI > 30 kg/m2 (OR 2.84; CI 1.15−7.01), ischemic heart disease (OR 3.65; CI 1.01−13.2), diabetes (OR 3.88; CI 1.38−10.9), frequent ventricular ectopy before operation (OR 9.78; CI 1.91−50.2), mitral valve repair (OR 4.47; CI 1.76−11.3), tricuspid valve repair (OR 3.06; CI 1.09−8.58), 3 and more procedures (OR 4.44; CI 1.67−11.8). Conclusions: The hospital mortality rate was 3%. The main indicators associated with the risk of death were: diabetes, overweight (body mass index more than 30 kg/m2), frequent ventricular ectopy before surgery, hemoglobin level below 120 g/L, hematocrit level below 39%, longer cardiopulmonary bypass time and aortic cross-clamp time, additional mitral and tricuspid valve interventions.

Surgical aortic valve replacement and left ventricular remodeling: Survival and sex-related differences

OBJECTIVES

To analyze how left ventricular (LV) remodeling and hypertrophy geometry evolve after surgical aortic valve replacement (SAVR) in octogenarian patients, and identify potential sex-related differences and implications for long-term outcomes.

METHODS

In 170 patients with aortic stenosis ([AS], age 80 ± 4 years, 59% women), hypertrophy geometry and remodeling (LV index) were reanalyzed one year post-SAVR. The six-year outcomes were evaluated.

RESULTS

Pre-SAVR, 65% of the women and 38.6% of the men (P < .001) showed adaptive remodeling. Concentric hypertrophy was prevalent in adaptive remodeling, and mixed and dilated hypertrophy were more prevalent in maladaptive remodeling. At one year, the remodeling patterns and sex distribution were similar to those observed pre-SAVR, but the LV index decreased in women and increased in men (P < .0001). Women with adaptive remodeling had a higher incidence of persistent concentric hypertrophy with higher LV filling pressures. Long-term survival was better in women and worse in men with adaptive remodeling (P = .039). Men with adaptive remodeling and men with concentric hypertrophy had the highest risk of cardiac death. This risk was similar between sexes for patients with maladaptive remodeling and dilated hypertrophy. Women with LV ejection fraction >55% had a lower risk of cardiac death than men.

CONCLUSIONS

The long-term outcomes of SAVR differ between sexes in older patients with AS and adaptive LV remodeling. The LV index facilitates studying the pathways of adaptation to AS. The follow-up shifts help explain the sex differences in long-term outcomes post-SAVR. Concentric hypertrophy is associated with the highest risk of cardiac death in men.

Clinical Value of Complex Echocardiographic Left Ventricular Hypertrophy Classification Based on Concentricity, Mass, and Volume Quantification

Echocardiography is the most validated, non-invasive and used approach to assess left ventricular hypertrophy (LVH). Alternative methods, specifically magnetic resonance imaging, provide high cost and practical challenges in large scale clinical application. To include a wide range of physiological and pathological conditions, LVH should be considered in conjunction with the LV remodeling assessment. The universally known 2-group classification of LVH only considers the estimation of LV mass and relative wall thickness (RWT) to be classifying variables. However, knowledge of the 2-group patterns provides particularly limited incremental prognostic information beyond LVH. Conversely, LV enlargement conveys independent prognostic utility beyond LV mass for incident heart failure. Therefore, a 4-group LVH subdivision based on LV mass, LV volume, and RWT has been recently suggested. This novel LVH classification is characterized by distinct differences in cardiac function, allowing clinicians to distinguish between different LV hemodynamic stress adaptations in various cardiovascular diseases. The new 4-group LVH classification has the advantage of optimizing the LVH diagnostic approach and the potential to improve the identification of maladaptive responses that warrant targeted therapy. In this review, we summarize the current knowledge on clinical value of this refinement of the LVH classification, emphasizing the role of echocardiography in applying contemporary proposed indexation methods and partition values.

Severe Aortic Valve Stenosis: Symptoms, Biochemical Markers, and Global Longitudinal Strain

BACKGROUND

According to the actual guidelines regarding severe aortic valve stenosis (AS), symptoms are the most important trigger for aortic valve replacement (AVR). However, the objective analysis of cardiological clinic can be confused, considering the aging population this disease affects and the comorbidities.

OBJECTIVES

Looking for an objective marker of disease, useful for scheduling the correct AVR, we researched the relation between some biochemical markers of left ventricular (LV) dysfunction and its global longitudinal strain.

MATERIALS AND METHODS

We analyzed 74 consecutive patients (82 ± 4 years) with severe AS. We identified 61 patients with symptoms (angina, dyspnea, and syncope) and 13 asymptomatic patients. The clinical and echocardiographic parameters were compared between these two groups. LV ejection fraction (LVEF), LV global longitudinal strain (LVGLS), NT-pro-B-type brain natriuretic peptide (BNP), troponin T (TNT), creatine kinase-MB (CPK-MB), and myoglobin were determined at the time of evaluation.

RESULTS

Compared with the asymptomatic group, patients in the symptomatic group had a lower LVGLS (P = 0.002) and an increased pro-BNP (P = 0.0002). LVGLS showed a good correlation with pro-BNP as a marker of myocardial damage, with a linear increase of pro-BNP in patients with a linear decrease of LVGLS (r = 0.43). Despite the normal value of LVEF > 50% in asymptomatic patients, some of them (46%) have an early dysfunction of LVGLS. No other statistically significant difference emerged from the biochemical analysis, in TNT (P = 0.29), CPK-MB (P = 0.36), and myoglobin (P = 0.38).

CONCLUSIONS

Pro-BNP and LVGLS can be considered an objective marker of clinical severity of AS disease, useful for management and scheduling of AVR, especially in asymptomatic patients.

WAS THE CLASSIFICATION ABLE TO DIVIDE DOGS WITH MYXOMATOUS MITRAL VALVE DISEASE ACCORDING TO THE SEVERITY OF THE DISEASE?

Using the simultaneous readings of the left ventricular remodeling model and the left ventricular weight to body weight ratio, the Gaasch and Zile classification was able to distinguish almost completely (95%) the dogs without pulmonary edema from those with pulmonary edema in cases of MMVD (myxomatous mitral valve disease) with an established limit for the left ventricular mass of 7.478 g/kg between the two groups. In one of the twenty animals surveyed, the classification failed. We assume that this is related to the exacerbation of the disease and the change of its chronic course due to an additional cause.

Differences in left ventricular geometry in hypertensive African-Europeans and Caucasian patients

BACKGROUND

There are data showing race-related differences regarding left ventricular (LV) geometry in hypertensive patients. Several authors reported that concentric remodeling is the most common remodeling pattern in hypertensive African-Americans, and this pattern may be related to prognosis. There is little information about the LV remodeling patterns in hypertensive Africans that migrated to Europe, which might have different distributions from those seen in African-Americans. The aim our study was to describe the prevalence of LV remodeling patterns in hypertensive African-Europeans and to compare it with that of hypertensive Caucasians.

METHODS

This is a descriptive study that included 135 consecutive treated hypertensive African-Europeans and 128 hypertensive Caucasians. Patients were examined by transthoracic echocardiography and categorized into the four classic geometric patterns according to LV mass index (LVMi) and relative wall thickness (RWT).

RESULTS

The mean age and gender distribution were similar in the 2 groups. Caucasians had significantly higher body mass index, LV diastolic and systolic diameters, while African-Europeans had higher RWT and interventricular septum thickness. No differences in LVMi was found. In the African-European group, the prevalence of normal pattern, concentric remodeling, concentric hypertrophy and eccentric hypertrophy were 13%, 36%, 45% and 6% respectively, while in Caucasians they were 21%, 33%, 34% and 12%, respectively. African-Europeans had a higher prevalence of concentric remodeling and hypertrophy compared to Caucasians (81% vs. 67%, p = .005).

CONCLUSIONS

This study shows important differences in LV geometry between treated African-European and Caucasian hypertensive patients. Also, African-Europeans may have slightly different characteristics compared to African-Americans.

Analysis of Regional Right Ventricular Function by Tissue Doppler Imaging in Patients with Aortic Stenosis

Background:

Right ventricular (RV) dysfunction is frequently observed in patients with aortic stenosis (AS). Nevertheless, assessment of regional RV deformation is yet not performed. The aim of the study was to analyze the impact of moderate and severe AS on global and regional RV function by a multisegmental approach using tissue Doppler imaging (TDI).

Methods:

In 50 patients (Group I – AS [n = 25] and Group II – normal controls [n = 25]), additional echocardiographic views of the RV were prospectively performed. The TDI sample volume was placed in the basal myocardial region of the anterior (RV-anterior), inferior (RV-inferior), and free RV wall (RV-free wall) to assess the following parameters: S'_RV, E'_RV, and A'_RV waves; IVCT_RV; IVRT_RV; and myocardial performance index (MPI_RV).

Results:

In AS patients, left ventricular (LV) mass index, left atrial (LA) volume index, and LV end-diastolic pressure were significantly increased. Moreover, AS patients had higher systolic pulmonary artery pressure (sPAP) and lower values for PV AccT (P < 0.0001), but TAPSE was not different between the two groups (P = 0.062). In AS patients, IVRT_RV-anterior, IVRT_RV-inferior, and IVRT_RV-freewall and MPI_RV were statistically increased (P < 0.0001). A significant correlation between IVRT_RV (evaluated at all three regions) and the parameters including sPAP, PV AccT, and E_LV/e'_LV ratio was observed in AS. A strong correlation was observed between IVRT_{RV-freewall/inferior} and AS severity by evaluation of velocities, gradient, and aortic valve area (P < 0.0001).

Conclusions:

The present study reports a correlation between the severity of AS and the increase of IVRT_RV and MPI_RV. Thus, a distinct analysis of RV performance is important for echocardiographic evaluation of patients with AS.

Value of ejection fraction/velocity ratio in the prognostic stratification of patients with asymptomatic aortic valve stenosis

BACKGROUND

The ejection fraction/velocity ratio (EFVR) is a simple function-corrected index of aortic stenosis severity with a good correlation with aortic valve area measured using the Gorlin formula at cardiac catheterization. It is calculated by dividing left ventricular ejection fraction (LVEF) to 4 × (peak jet velocity)² .

OBJECTIVE

Our aim was to evaluate the value of EFVR in predicting adverse events in patients with asymptomatic aortic stenosis.

METHODS

We analyzed the clinical and echocardiographic data of 216 asymptomatic patients with at least moderate aortic stenosis (AVA ≤ 1.5 cm² ). The primary end-point was cardiovascular death or aortic valve replacement.

RESULTS

There were 119 (55%) men and mean age was 68 ± 10 years. The mean follow-up time was 4.2 ± 1.6 years (median 4.3 years). During follow-up, the composite end-point of death or aortic valve replacement was reached in 105 patients (49%). Using multivariate Cox regression analysis, EFVR and valvulo-arterial impedance emerged as independent variables associated with outcome (P < 0.001 and P = 0.001, respectively). In the subgroup of patients with severe aortic stenosis (AVA < 1 cm² ), EFVR ≤ 0.9 was associated with an increased hazard ratio for the composite end-point of mortality and aortic valve replacement (HR 2.14, 95% CI: 1.15-4.0, P = 0.017), even after adjusting for aortic valve area.

CONCLUSIONS

In patients with asymptomatic moderate to severe aortic stenosis, EFVR is useful for risk stratification. Our results suggest that incorporating EFVR in the evaluation of patients with asymptomatic aortic stenosis might help identify those who are most likely to benefit from early elective aortic replacement.