Association of Inadequately Low Left Ventricular Mass with Enhanced Myocardial Contractility in Severe Degenerative Aortic Stenosis

Physical health effects of sedentary behaviour on adults with an intellectual disability: A scoping review

This literature review was designed to establish the effects of sedentary behaviour on the physical health of adults with an intellectual disability. Sedentary behaviour is defined as any waking behaviour characterized by an energy expenditure of ≤1.5 METs while in a sitting, lying or reclining posture. An extensive search was executed in six databases: EMBASE, Medline, CINAHL, PsycINFO, ASSIA and Web of Science. Following screening, 18 articles remained for inclusion in the review. A thematic analysis using the Braun and Clarke six step process resulted in the identification of seven broad health areas. Studies showed a prevalence of obesity, multimorbidity and metabolic syndrome as well as elevated levels of sedentary behaviour in adults with an intellectual disability. This literature review demonstrated that sedentary behaviour could be a contributor to the poor health which is common in adults with an intellectual disability. However to date the body of evidence does not confirm a cause-and-effect relationship.

Clinical, echocardiographic and prognostic outcomes of patients with concordant and discordant high-gradient aortic stenosis in an Asian cohort

Literature of patients with severe high-gradient aortic stenosis (HG AS) (mean pressure gradient [MPG] ≥ 40 mmHg and aortic valve area [AVA] ≥ 1.0 cm2) remains limited. This study seeks to compare the prognostic outcomes of patients with high-gradient concordant (HGCON-AS) and discordant AS (HGDIS-AS) in an Asian cohort. From 2010 to 2015, patients with moderate-to-severe AS with preserved left ventricular ejection fraction (LVEF ≥ 50%) were recruited and stratified into 3 groups based on index echocardiogram-(1) HGDIS-AS, (2) HGCON-AS and (3) moderate AS (MOD-AS). The primary study endpoints was all-cause mortality, with secondary endpoints of congestive heart failure (CHF) admissions and aortic valve replacement (AVR). Multivariable Cox regression was used and Kaplan-Meier curves were constructed to evaluate associations between HGDIS-AS, HGCON-AS and MOD-AS, and the study outcomes. A total of 467 patients were studied, comprising of 6.2% HGDIS-AS, 13.9% HGCON-AS and 79.9% MOD-AS patients. There was significantly higher AVR rates in the HGCON-AS group (58.5%), followed by HGDIS-AS (31.0%) and MOD-AS (4.6%), p < 0.001) groups. After adjusting for confounders, HGCON-AS was significantly associated with all-cause mortality (HR 3.082, 95% CI 1.479-6.420, p = 0.003) and CHF admissions (HR 12.728, 95% CI 2.922-55.440 p = 0.001) but not HGDIS-AS, with MOD-AS as the reference group. Both HGDIS-AS (HR 7.715, 95% CI 2.927-20.338; p < 0.001) and HGCON-AS (HR 21.960, 95% CI 10.833-44.515, p < 0.001) were independent predictors of AVR. After exclusion of reversible high-flow states, HGDIS-AS patients appear to have a more favourable prognostic profile compared to HGCON-AS patients. Large prospective interventional studies examining the prognostic differences between the two groups will be the next important step.

Impaired Left Ventricular Circumferential Midwall Systolic Performance Appears Linked to Depressed Preload, but Not Intrinsic Contractile Dysfunction or Excessive Afterload, in Paradoxical Low-Flow/Low-Gradient Severe Aortic Stenosis

Paradoxical low-flow/low-gradient aortic stenosis (P-LFLG-AS) occurs in about one-third of patients with severe AS and preserved left ventricular (LV) ejection fraction (EF). Our aim was to differentiate between altered LV loading conditions and contractility as determinants of subtle LV systolic dysfunction in P-LFLG-AS. We retrospectively analyzed medical records of patients with isolated severe degenerative AS and preserved EF (30 subjects with P-LFLG-AS and 30 patients with normal-flow/high-gradient severe AS (NFHG-AS)), without relevant coexistent diseases (e.g., diabetes, coronary artery disease and chronic kidney disease) or any abnormalities which could account for a low-flow state. Patients with P-LFLG-AS and NFHG-AS did not differ in aortic valve area index and most clinical characteristics. Compared to NFHG-AS, subjects with P-LFLG-AS exhibited smaller LV end-diastolic diameter (LVd) (44 ± 5 vs. 54 ± 5 mm, p < 0.001) (consistent with lower LV preload) with pronounced concentric remodeling, higher valvulo-arterial impedance (3.8 ± 1.1 vs. 2.2 ± 0.5 mmHg per mL/m2, p < 0.001) and diminished systemic arterial compliance (0.45 ± 0.11 vs. 0.76 ± 0.23 mL/m2 per mmHg, p < 0.001), while circumferential end-systolic LV midwall stress (cESS), an estimate of afterload at the LV level, was similar in P-LFLG-AS and NFHG-AS (175 ± 83 vs. 198 ± 69 hPa, p = 0.3). LV midwall fractional shortening (mwFS) was depressed in P-LFLG-AS vs. NFHG-AS (12.3 ± 3.5 vs. 14.7 ± 2.9%, p = 0.006) despite similar EF (61 ± 6 vs. 59 ± 8%, p = 0.4). By multiple regression, the presence of P-LFLG-AS remained a significant predictor of lower mwFS compared to NFHG-AS upon adjustment for cESS (β ± SEM: −2.35 ± 0.67, p < 0.001); however, the significance was lost after further correction for LVd (β = −1.10 ± 0.85, p = 0.21). In conclusion, the association of P-LFLG-AS with a lower cESS-adjusted mwFS, an index of afterload-corrected LV circumferential systolic function at the midwall level, appears secondary to a smaller LV end-diastolic cavity size according to the Frank−Starling law. Thus, low LV preload, not intrinsic contractile dysfunction or excessive afterload, may account for impaired LV circumferential midwall systolic performance in P-LFLG-AS.

Inadequately low left ventricular mass in patients with significant aortic stenosis predicts favourable prognostic outcomes

In patients with significant aortic stenosis (AS), the prognostic effect of the increase in left ventricular mass (LVM) in relation to one's hemodynamic load has been described. Inappropriately high LVM has been shown to predict adverse cardiovascular events. However, little is known about the prognostic impact of inadequately low LVM (i-lowLVM) in patients with significant AS. I-lowLVM was defined as the measured LVM < 73% of the predicted LVM based on sex, stroke work and height from the reference adult population, used in previous established studies. For outcome analysis, the end-point was defined as all-cause mortality, aortic valve replacement and/or admission for congestive heart failure. Kaplan-Meier curves and multivariable Cox regression models were constructed to compare outcomes on follow-up. During the follow-up (4.5 ± 4.1 years), 132 patients (11.1%) had i-lowLVM, 868 (73.1%) had adequate-LVM, 188 (15.8%) had inappropriately high LVM. Outcome analysis only included patients with i-lowLVM and adequate-LVM (N = 1000). An adverse composite event occurred in 41.7% of the i-lowLVM group and 52.4% of the adequate-LVM group (p = 0.021). Event-free survival in patients with i-lowLVM and appropriate-LVM was 76% versus 68% at 2-year, 55% versus 46% at 4-year, 33% versus 27% at 6-year, 20% versus 17% at 8-year, and 17% versus 11% at 10-year follow-up, respectively (p < 0.001). Cox analysis revealed that i-lowLVM was independently associated with lower composite adverse outcome (HR 0.624, 95% CI 0.460-0.846, p = 0.002) after adjusting for sex, age, ejection fraction, ischemic heart disease, diabetes and transaortic valve mean gradient. In the separate Cox subanalyses, the presence of i-lowLVM remained a predictor of lower composite adverse outcome in the severe AS subgroup (HR 0.587, 95% CI 0.396-0.870, p = 0.008), and the LVH subgroup (HR 0.574, 95% CI 0.401-0.824, p = 0.003) after adjusting for confounders. I-lowLVM despite significant AS may represent a distinct group that is associated with improved survival outcomes independent of other prognostic covariates.

Better Myocardial Function in Aortic Stenosis with Low Left Ventricular Mass: A Mechanism of Protection against Heart Failure Regardless of Stenosis Severity?

About one-tenth to one-third of patients with severe aortic stenosis (AS) do not develop left ventricular hypertrophy (LVH). Intriguingly, the absence of LVH despite severe AS is associated with lower prevalence of heart failure (HF), which challenges the classical notion of LVH as a beneficial compensatory response. Notably, the few studies that have attempted to characterize AS subjects with inadequately low left ventricular (LV) mass relative to LV afterload (i-lowLVM) described better prognosis and enhanced LV performance in AS associated with i-lowLVM, but those reports were limited to severe AS. Our aim was to compare myocardial function between moderate and severe AS with i-lowLVM. We retrospectively analyzed in-hospital records of 225 clinically stable nondiabetic patients with isolated moderate or severe degenerative AS in sinus rhythm, free of coexistent diseases. Subjects with i-lowLVM were compared to those with appropriate or excessive LVM (a/e-LVM), defined on the basis of the ratio of a measured LVM to the LVM predicted from an individual hemodynamic load. Patients with i-lowLVM and a/e-LVM did not differ in aortic valve area, LV end-diastolic diameter (LVd, a measure of LV preload), and circumferential end-systolic LV wall stress (cESS), an estimate of LV afterload. Compared to a/e-LVM, patients with i-lowLVM had increased LV ejection fraction (EF) and especially higher LV midwall fractional shortening (a better index of LV myocardial function than EF in concentric LV geometry) (p < 0.001–0.01), in both moderate and severe AS. LVd and cESS were similar in the four subgroups of the study subjects, i.e., moderate AS with i-lowLVM, moderate AS with a/e-LVM, severe AS with i-lowLVM, and severe AS with a/e-LVM (p > 0.6). Among patients with i-lowLVM, LVM did not differ significantly between moderate and severe AS (p > 0.4), while in those with a/e-LVM, LVM was increased in severe versus moderate AS (p < 0.001). In conclusion, the association of the low-LVM phenotype with better myocardial contractility may already develop in moderate AS. Additionally, cESS appears to be a controlled variable, which is kept constant over AS progression irrespective of LVM category, but even when controlled (by increasing LVM), is not able to prevent deterioration of LV function. Whether improved myocardial performance contributes to favorable prognosis and the preventive effect against HF in AS without LVH, remains to be studied.

Depressed systemic arterial compliance and impaired left ventricular midwall performance in aortic stenosis with concomitant type 2 diabetes: a retrospective cross-sectional study

Background

Degenerative aortic stenosis (AS), a disease of the elderly, frequently coexists with concomitant diseases, including type 2 diabetes (T2DM) which amplifies the cardiovascular (CV) risk. T2DM affects left ventricular (LV) structure and function via hemodynamic and metabolic factors. In concentric LV geometry, typical for AS, indices of LV midwall mechanics are better estimates of LV function than ejection fraction (EF). Effects of T2DM coexisting with AS on circumferential LV midwall systolic function and large artery properties have not been reported so far. Our aim was to compare characteristics of AS patients with and without T2DM, with a focus on LV midwall systolic function and arterial compliance.

Methods

Medical records of 130 electively hospitalized patients with moderate or severe isolated degenerative AS were retrospectively analyzed. Exclusion criteria included clinical instability, atrial fibrillation, coronary artery disease and relevant non-cardiac diseases. From in-hospital echocardiography and blood pressure, we calculated LV midwall fractional shortening (mwFS), circumferential end-systolic LV wall stress (cESS) and valvulo-arterial impedance (Zva), estimates of LV afterload, as well as systemic arterial compliance.

Results

Patients with (n = 50) and without T2DM (n = 80) did not differ in age, AS severity, LV mass and LV diastolic diameter. T2DM patients exhibited elevated cESS (247 ± 105 vs. 209 ± 84 hPa, p = 0.025) and Zva (5.8 ± 2.2 vs. 5.1 ± 1.8 mmHg per mL/m², p = 0.04), and lower stroke volume index (33 ± 10 vs. 38 ± 12 mL/m², p = 0.01) and systemic arterial compliance (0.53 ± 0.16 vs. 0.62 ± 0.22 mL/m² per mmHg, p = 0.01). mwFS (11.9 ± 3.9 vs. 14.1 ± 3.7%, p = 0.001), but not EF (51 ± 14 vs. 54 ± 13%, p = n.s.), was reduced in T2DM. mwFS and cESS were inversely interrelated in patients both with (r = − 0.59, p < 0.001) and without T2DM (r = − 0.53, p < 0.001) By multiple regression, higher cESS (p < 0.001) and T2DM (p = 0.02) were independent predictors of depressed mwFS.

Conclusions

In AS, coexistent T2DM appears associated with reduced systemic arterial compliance and LV dysfunction at the midwall level, corresponding to slightly depressed myocardial contractility.

Electronic supplementary material

The online version of this article (10.1186/s12933-019-0894-1) contains supplementary material, which is available to authorized users.

Remodeling classification system considering left ventricular volume in patients with aortic valve stenosis: Association with adverse cardiovascular outcomes

BACKGROUND

To assess prevalence and clinical implications of left ventricular (LV) remodeling considering: LV volume, mass and relative wall thickness at the time of aortic valve stenosis diagnosis.

METHODS AND RESULTS

We retrospectively analyzed 343 patients (age 79.2 ± 9.5 years, 48.1% males) with functional aortic valve area (AVA) ≤ 1.5 cm² . LV geometric patterns and clinical outcomes (combined death, cardiac hospitalization, aortic valve replacement [AVR]) were evaluated. According to the new LV remodeling classification, 4.9% had normal geometry, 7.5% concentric remodeling, 39.3% concentric hypertrophy (LVH), 22.4% mixed LVH, 12.5% dilated LVH, 3.2% eccentric LVH and 4.3% eccentric remodeling, 5.5% had not classifiable LVH. Indexed stroke volume (SVi) was higher in patients with concentric LVH (40.3 ± 11.9 mL/m² ) and mixed LVH (41.6 ± 13.4 mL/m² ) and lower in patients with eccentric LVH (24.9 ± 7.7 mL/m² ), concentric (36.6 ± 12.7 mL/m² ) and eccentric remodeling (34.9 ± 9.5 mL/m² ), P = 0.003. During a median follow-up of 2.2 years, 260 (75.8%) had the combined end point. A significant association between the combined end point and LV dilation (P = 0.010) or LV remodeling patterns (P = 0.0001) was found. After multivariable adjustment for AVR, concentric remodeling (HR 3.12, IC 95% 1.14-8.55; P = 0.02) and dilated LVH (HR 3.48, IC 95% 1.31-9.27; P = 0.01) were strongly associated with death or cardiac hospitalizations.

CONCLUSIONS

In patients with AVA ≤ 1.5 cm² , when the new LV remodeling classification system is applied, only a minority had normal geometry and less than half had "classic" concentric LVH or remodeling. LV volume dilatation is frequent and associated with adverse outcome. Concentric remodeling, eccentric remodeling, dilated LVH had the worst noninvasive hemodynamic profile and prognosis.