Left ventricular concentric geometry predicts incident diabetes mellitus independent of established risk factors in the general population: the Copenhagen City Heart Study

Background

Subtle impairments in left ventricular (LV) function and geometry are common findings in individuals with diabetes. However, whether these impairments precede the development of diabetes mellitus (DM) is not entirely clear.

Methods

Echocardiograms from 1710 individuals from the general population free of prevalent diabetes mellitus were analyzed. Left ventricular (LV) concentric geometry was defined as either LV concentric remodeling or LV concentric hypertrophy as directed in contemporary guidelines. The severity of LV concentricity was assessed by relative wall thickness (RWT) calculated as posterior wall thickness (PWT) indexed to left ventricular internal diameter at end diastole (LVIDd) (RWT = 2 * PWT/LVIDd). End-point was incident DM.

Results

Median follow-up time was 12.6 years (IQR: 12.0–12.8 years). Follow-up was a 100%. A total of 55 participants (3.3%) developed DM during follow-up. At baseline, the prevalence of a concentric LV geometric pattern was significantly higher (41.8% vs 20.3%, p < 0.001) in individuals who developed DM during follow-up. In a final multivariable model adjusting for established DM risk factors including HbA1c, BMI and plasma glucose, LV concentric geometry and RWT remained significantly associated with incident DM (LV concentric geometry: HR 1.99, 95% CI 1.11–3.57, p = 0.021) (RWT: HR 1.41, 95% CI 1.06–1.86, p = 0.017, per 0.1 increase). This association remained despite adjustment for established risk factors for DM.

Conclusion

Altered LV geometry may precede the development of DM. LV concentric geometry determined by echocardiography and the severity of LV concentricity evaluated as RWT are associated with incident DM in the general population.

Electronic supplementary material

The online version of this article (10.1186/s12933-019-0842-0) contains supplementary material, which is available to authorized users.

Myocardial Strain and Dyssynchrony: Incremental Value?

Heart failure (HF) has evolved in an epidemic manner and constitutes a major public health issue. Currently, several prognostic markers and treatment options exist to guide treatment of HF with reduced ejection fraction, but echocardiographic deformation imaging suggests novel pathophysiologic aspects that could help optimize treatment further. Even though no formal treatment options currently exist for patients with HF with preserved ejection fraction, some HF medication does seem to attenuate strain measures. Speckle tracking has furthermore helped characterize this condition and to confer prognostic information. Thus, strain imaging could facilitate novel trials, and thereby hopefully introduce treatment opportunities.

Post-systolic shortening predicts heart failure following acute coronary syndrome

BACKGROUND

Post-systolic shortening (PSS) is a novel echocardiographic marker of myocardial dysfunction. Our objective was to assess the prognostic value of PSS in patients following acute coronary syndrome (ACS) who underwent percutaneous coronary intervention (PCI).

METHODS

A total of 428 patients hospitalized for ACS (mean age 64 ± 12 years, male 73%) underwent speckle tracking echocardiography following treatment with PCI (median 2 days). The individual endpoints were heart failure (HF), myocardial infarction (MI) and all-cause death. We excluded known HF. Presence of PSS was defined as post-systolic displacement ≥20% of maximum strain in one cardiac cycle. The post-systolic index (PSI) was defined as (100 × [maximum-strain cardiac cycle - peak-systolic strain])/(maximum-strain cardiac cycle)].

RESULTS

During median follow-up of 3.7 years (IQR 0.3, 5.2), 155 patients (36%) experienced HF, 52 (12%) had MI and 87 (20%) died from all causes. Patients experiencing HF had more walls displaying PSS (3.2 vs. 1.9 walls) and higher PSI (22% vs. 12%) (P < 0.001 both). In Cox proportional hazards models adjusted for baseline characteristics, invasive and echocardiographic measurements, the risk of HF increased incrementally with increasing number of walls with PSS (HR 1.28 95%CI 1.12-1.46, P < 0.001 per 1 increase in walls with PSS). The PSI remained an independent predictor of HF after adjustment (HR 1.61 95%CI 1.21-2.12, P = 0.001 per 1% increase). In the same adjusted models, MI and all-cause death were not significantly associated with PSS.

CONCLUSION

Presence of PSS provides novel and independent prognostic information regarding the risk of future HF in patients with ACS following PCI.

Post-systolic shortening: normal values and association with validated echocardiographic and invasive measures of cardiac function

Post-systolic shortening (PSS) does not contribute to the ejection of blood and may inhibit diastolic filling. We determined normal values of PSS in healthy subjects and investigated associations with echocardiographic and invasive measures of systolic and diastolic function. We prospectively analyzed participants from the general population (n = 620, mean age 47 ± 14 years) with no cardiovascular disease. Participants underwent echocardiography, including speckle tracking assessment of the post-systolic index (PSI), strain and time. We defined the PSI as: 100 × [(peak global longitudinal strain - peak systolic longitudinal strain)/(peak global longitudinal strain)]. We also included stable patients (n = 44) referred for left ventricle (LV) catheterization and echocardiography. Normal values: median PSI 2.0% (IQR 0.7, 4.8), post-systolic strain 0.4% (IQR 0.2, 0.8) and post-systolic time 22.6 ms (IQR 10.7, 40.8). Sex modified the relationship between PSI and age (P interaction = 0.037), such that PSI increased with age in women but not in men. PSI was associated with diastolic function (e', E/e' and E/A) (P < 0.05 for all), but not with LV ejection fraction (P = 0.08). PSI was associated with invasively measured LV pressure decline in early diastole, dP/dt min ([Formula: see text] = 0.12, P = 0.010), but not with LV pressure rise in early systole, dP/dt max ([Formula: see text]= - 0.05, P = 0.30). A PSI > 5% had 82% specificity and 99% sensitivity for identifying impaired LV systolic and/or diastolic function. Normal values of PSS are modified by sex. The PSI is associated with most validated echocardiographic and invasive measures of cardiac systolic and diastolic function.

Machine learning-based phenogrouping in heart failure to identify responders to cardiac resynchronization therapy

AIMS

We tested the hypothesis that a machine learning (ML) algorithm utilizing both complex echocardiographic data and clinical parameters could be used to phenogroup a heart failure (HF) cohort and identify patients with beneficial response to cardiac resynchronization therapy (CRT).

METHODS AND RESULTS

We studied 1106 HF patients from the Multicenter Automatic Defibrillator Implantation Trial with Cardiac Resynchronization Therapy (MADIT-CRT) (left ventricular ejection fraction ≤ 30%, QRS ≥ 130 ms, New York Heart Association class ≤ II) randomized to CRT with a defibrillator (CRT-D, n = 677) or an implantable cardioverter defibrillator (ICD, n = 429). An unsupervised ML algorithm (Multiple Kernel Learning and K-means clustering) was used to categorize subjects by similarities in clinical parameters, and left ventricular volume and deformation traces at baseline into mutually exclusive groups. The treatment effect of CRT-D on the primary outcome (all-cause death or HF event) and on volume response was compared among these groups. Our analysis identified four phenogroups, significantly different in the majority of baseline clinical characteristics, biomarker values, measures of left and right ventricular structure and function and the primary outcome occurrence. Two phenogroups included a higher proportion of known clinical characteristics predictive of CRT response, and were associated with a substantially better treatment effect of CRT-D on the primary outcome [hazard ratio (HR) 0.35; 95% confidence interval (CI) 0.19-0.64; P = 0.0005 and HR 0.36; 95% CI 0.19-0.68; P = 0.001] than observed in the other groups (interaction P = 0.02).

CONCLUSIONS

Our results serve as a proof-of-concept that, by integrating clinical parameters and full heart cycle imaging data, unsupervised ML can provide a clinically meaningful classification of a phenotypically heterogeneous HF cohort and might aid in optimizing the rate of responders to specific therapies.

Prognostic importance of mechanical dyssynchrony in predicting heart failure development after ST-segment elevation myocardial infarction

The aim of this study is to assess the prognostic value of mechanical dyssynchrony defined as the standard deviation of the time to peak longitudinal strain (SD T2P LS) in predicting the development of heart failure (HF) after an ST-segment elevation myocardial infarction (STEMI). Three hundred and seventy-three patients were admitted with STEMI and treated with primary percutaneous coronary intervention. Left ventricular (LV) mechanical dyssynchrony was examined through speckle tracking echocardiography and defined as SD T2P LS. The association with the outcome of HF hospitalization was assessed using Cox proportional hazard models. During a median follow-up of 5.12 years, 144 patients (38.6%) were admitted due to HF. Worse dyssynchrony was associated with the outcome in unadjusted and multivariable analysis (multivariable hazard ratio 1.05, 95% confidence interval 1.00-1.10, p-value 0.039, per 10 ms increase), but not after further adjustment for LV ejection fraction (LVEF), E/e' and global longitudinal strain (GLS) (hazard ratio 1.01, 95% confidence interval 1.00-1.07, p-value 0.71, per 10 ms increase), nor in a model only adjusting for GLS (hazard ratio 1.01, 95% confidence interval 1.00-1.06, p-value 0.61, per 10 ms increase). These findings were reproduced in a competing risk analysis treating all-cause mortality as a competing risk. LV mechanical dyssynchrony, as assessed by SD T2P LS is not an independent predictor of post-STEMI HF development and mechanical dyssynchrony does not provide independent prognostic information regarding HF when GLS is known.

Echo and heart failure: when do people need an echo, and when do they need natriuretic peptides?

Heart failure (HF) is a threat to public health. Heterogeneities in aetiology and phenotype complicate the diagnosis and management of HF. This is especially true when considering HF with preserved ejection fraction (HFpEF), which makes up 50% of HF cases. Natriuretic peptides may aid in establishing a working diagnosis in patients suspected of HF, but echocardiography remains the optimal choice for diagnosing HF. Echocardiography provides important prognostic information in both HF with reduced ejection fraction (HFrEF) and HFpEF. Traditionally, emphasis has been put on the left ventricular ejection fraction (LVEF). LVEF is useful for both diagnosis and prognosis in HFrEF. However, echocardiography offers more than this single parameter of systolic function, and for optimal risk assessment in HFrEF, an echocardiogram evaluating systolic, diastolic, left atrial and right ventricular function is beneficial. In this assessment echocardiographic modalities such as global longitudinal strain (GLS) by 2D speckle-tracking may be useful. LVEF offers little value in HFpEF and is neither helpful for diagnosis nor prognosis. Diastolic function quantified by E/e′ and systolic function determined by GLS offer prognostic insight in HFpEF. In HFpEF, other parameters of cardiac performance such as left atrial and right ventricular function evaluated by echocardiography also contribute with prognostic information. Hence, it is important to consider the entire echocardiogram and not focus solely on systolic function. Future research should focus on combining echocardiographic parameters into risk prediction models to adopt a more personalized approach to prognosis instead of identifying yet another echocardiographic biomarker.

Genome-Wide Associations of Global Electrical Heterogeneity ECG Phenotype: The ARIC (Atherosclerosis Risk in Communities) Study and CHS (Cardiovascular Health Study)

BACKGROUND

ECG global electrical heterogeneity (GEH) is associated with sudden cardiac death. We hypothesized that a genome-wide association study would identify genetic loci related to GEH.

METHODS AND RESULTS

We tested genotyped and imputed variants in black (N=3057) and white (N=10 769) participants in the ARIC (Atherosclerosis Risk in Communities) study and CHS (Cardiovascular Health Study). GEH (QRS-T angle, sum absolute QRST integral, spatial ventricular gradient magnitude, elevation, azimuth) was measured on 12-lead ECGs. Linear regression models were constructed with each GEH variable as an outcome, adjusted for age, sex, height, body mass index, study site, and principal components to account for ancestry. GWAS identified 10 loci that showed genome-wide significant association with GEH in whites or joint ancestry. The strongest signal (rs7301677, near TBX3) was associated with QRS-T angle (white standardized β+0.16 [95% CI 0.13-0.19]; P=1.5×10-26), spatial ventricular gradient elevation (+0.11 [0.08-0.14]; P=2.1×10-12), and spatial ventricular gradient magnitude (-0.12 [95% CI -0.15 to -0.09]; P=5.9×10-15). Altogether, GEH-SNPs explained 1.1% to 1.6% of GEH variance. Loci on chromosomes 4 (near HMCN2), 5 (IGF1R), 11 (11p11.2 region cluster), and 7 (near ACTB) are novel ECG phenotype-associated loci. Several loci significantly associated with gene expression in the left ventricle (HMCN2 locus-with HMCN2; IGF1R locus-with IGF1R), and atria (RP11-481J2.2 locus-with expression of a long non-coding RNA and NDRG4).

CONCLUSIONS

We identified 10 genetic loci associated with ECG GEH. Replication of GEH GWAS findings in independent cohorts is warranted. Further studies of GEH-loci may uncover mechanisms of arrhythmogenic remodeling in response to cardiovascular risk factors.

Postsystolic Shortening by Speckle Tracking Echocardiography Is an Independent Predictor of Cardiovascular Events and Mortality in the General Population

Background

Postsystolic shortening (PSS) has been proposed as a novel marker of contractile dysfunction in the myocardium. Our objective was to assess the prognostic potential of PSS on cardiovascular events and death in the general population.

Methods and Results

The study design consisted of a prospective cohort study of 1296 low‐risk participants from the general population, who were examined by speckle tracking echocardiography. The primary end point was the composite of heart failure, myocardial infarction, and cardiovascular death, defined as major adverse cardiovascular events (MACEs). The secondary end point was all‐cause death. The postsystolic index (PSI) was defined as follows: [(maximum strain in cardiac cycle−peak systolic strain)/(maximum strain in cardiac cycle)]×100. PSS was regarded as present if PSI >20%. During a median follow‐up of 11 years, 149 participants (12%) were diagnosed as having MACEs and 236 participants (18%) died. Increasing number of walls with PSS predicted both end points, an association that persisted after adjustment for age, sex, estimated glomerular filtration rate, global longitudinal strain, hypertension, heart rate, left ventricular ejection fraction, LV mass index, pro‐B‐type natriuretic peptide, previous ischemic heart disease, systolic blood pressure, average peak early diastolic longitudinal mitral annular velocity (e′), ratio between peak transmitral early and late diastolic inflow velocity (E/A), and left atrial volume index: MACEs (hazard ratio, 1.35; 95% confidence interval, 1.09–1.67; P=0.006 per 1 increase in walls displaying PSS) and death (hazard ratio, 1.30; 95% confidence interval, 1.08–1.57; P=0.006 per 1 increase in walls displaying PSS). The strongest predictor of end points was ≥2 walls exhibiting PSS. The PSI also predicted increased risk of the end points, and the associations remained significant in multivariable models: MACEs (per 1% increase in PSI: hazard ratio, 1.18; 95% confidence interval, 1.02–1.36; P=0.024) and death (per 1% increase in PSI: hazard ratio, 1.18; 95% confidence interval, 1.05–1.33; P=0.005).

Conclusions

Presence of PSS in the general population provides independent and long‐term prognostic information on the occurrence of MACEs and death.

Global ECG Measures and Cardiac Structure and Function: The ARIC Study (Atherosclerosis Risk in Communities)

BACKGROUND

Electric excitation initiates myocardial mechanical contraction and coordinates myocardial pumping. We hypothesized that ECG global electric heterogeneity (GEH) and its longitudinal changes are associated with cardiac structure and function.

METHODS AND RESULTS

Participants from the ARIC study (Atherosclerosis Risk in Communities) (N=5114; 58% female; 22% blacks) with resting 12-lead ECGs (visits 1-5) and echocardiographic assessment of left ventricular (LV) ejection fraction, LV global longitudinal strain, LV mass index, LV end-diastolic volume index, and LV end-systolic volume index at visit 5 were included. Longitudinal analysis included ARIC participants (N=14 609) with measured GEH at visits 1 to 4. GEH was quantified by spatial ventricular gradient, QRS-T angle, and sum absolute QRS-T integral. Cross-sectional and longitudinal regressions were adjusted for manifest and subclinical cardiovascular disease. Having 4 abnormal GEH parameters was associated with a 6.4% (95% confidence interval, 5.5-7.3) LV ejection fraction decline, a 24.2 g/m2 (95% confidence interval, 21.5-26.9) increase in LV mass index, a 10.3 mL/m2 (95% confidence interval, 8.9-11.7) increase in LV end-diastolic volume index, and a 7.8 mL/m2 (95% confidence interval, 6.9-8.6) increase in LV end-systolic volume index. Altogether, clinical and ECG parameters accounted for approximately one third of LV volume and 20% of systolic function variability. The associations were significantly stronger in cardiovascular disease. Sum absolute QRS-T integral increased by 20 mV*ms for each 3-year period in participants who demonstrated LV dilatation at visit 5. Sudden cardiac death victims demonstrated rapid GEH worsening, whereas those with LV dysfunction demonstrated slow GEH worsening. Healthy aging was associated with a distinct pattern of spatial ventricular gradient azimuth decrement.

CONCLUSIONS

GEH is a marker of subclinical abnormalities in cardiac structure and function.

Prognostic Value of Echocardiography in Hypertensive Versus Nonhypertensive Participants From the General Population

Hypertension may be the most significant cardiovascular risk factor. Few studies have assessed the prognostic value of echocardiography in hypertensive individuals. This study examines the incremental prognostic value of adding echocardiographic parameters to established risk factors in individuals from the general population with and without hypertension. A total of 1294 individuals from the general population underwent a health examination and an echocardiogram including 2-dimensional speckle tracking. Outcome was a composite of ischemic heart disease and heart failure. The prevalence of hypertension was 38.3%. During a median follow-up of 12.5 years (interquartile range, 9.4-12.8 years), 222 participants (17.2%) developed the outcome. Out of these 222 events, 145 (65%) occurred in hypertensive participants, whereas 77 (35%) occurred in nonhypertensive individuals, corresponding to an incidence rate of 32/(1000×person-years) and 8/(1000×person-years), respectively. Follow-up was 100%. After multivariable adjustment, only left ventricular mass index predicted the outcome in hypertensive individuals, whereas only global longitudinal strain predicted the outcome in nonhypertensive individuals. In hypertensive individuals the prognostic value of left ventricular mass index was incremental to SCORE and abnormal ECG status. In nonhypertensive individuals the prognostic value of global longitudinal strain was incremental to SCORE and abnormal ECG status. The prognostic value of echocardiography in predicting cardiovascular outcomes in the general population is altered by hypertension. In hypertensive individuals, left ventricular mass index added incremental prognostic value in addition to established risk factors. In nonhypertensive individuals, global longitudinal strain added incremental prognostic value in addition to established risk factors.

Ideal Cardiovascular Health and the Prevalence and Severity of Aortic Stenosis in Elderly Patients

Background

The relationship between ideal cardiovascular health reflected in the cardiovascular health score (CVHS) and valvular heart disease is not known. The purpose of this study was to determine the association of CVHS attainment through midlife to late life with aortic stenosis prevalence and severity in late life.

Methods and Results

The following 6 ideal cardiovascular health metrics were assessed in ARIC (Atherosclerosis Risk in Communities) Study participants at 5 examination visits between 1987 and 2013 (visits 1–4 in 1987–1998 and visit 5 in 2011–2013): smoking, body mass index, total cholesterol, blood pressure, physical activity, and blood glucose. Percentage attained CVHS was calculated in 6034 participants as the sum of CVHS at each visit/the maximum possible score. Aortic stenosis was assessed by echocardiography at visit 5 on the basis of the peak aortic valve velocity. Aortic stenosis was categorized sclerosis, mild stenosis, and moderate‐to‐severe stenosis. Mean age was 76±5 years, 42% were men, and 22% were black. Mean percentage attained CVHS was 63±14%, and the prevalence of aortic stenosis stages were 15.9% for sclerosis, 4.3% for mild stenosis, and 0.7% for moderate‐to‐severe stenosis. Worse percentage attained CVHS was associated with higher prevalence of aortic sclerosis (P<0.001 for trend), mild stenosis (P<0.001), and moderate‐to‐severe stenosis (P=0.002), adjusting for age, sex, and race.

Conclusions

Greater attainment of ideal cardiovascular health in midlife to late life is associated with a lower prevalence of aortic sclerosis and stenosis in late life in a large cohort of older adults.

Impact of transducer frequency setting on speckle tracking measures

Speckle tracking echocardiography is an emerging technique, which is currently being included in clinical guidelines. We sought to investigate the impact of transducer frequency settings on speckle tracking derived measures. The study comprised of 22 subjects prospectively enrolled for a randomized controlled trial (LOOP-study, Clinicaltrials.gov:NCT02036450). Patients were above 70 years of age with increased risk of stroke, and had an echocardiogram performed, which included focused images of the left ventricle. Focused images were obtained with the transducer frequency set at both 1.7/3.3 and 1.5/3.0 MHz. The images were obtained immediately after each other at the exact same position for the two settings. Speckle tracking was performed in three apical projections, allowing for acquisition of layered global longitudinal strain (GLS) and strain rate measures. Concordance between the frequency settings was tested for endo-, mid-, and epicardial GLS and strain rates by coefficients of variation, bias coefficients and visually displayed by Bland-Altman plots. Bland-Altman plots did not reveal any significant over- or underestimation of any speckle tracking measure. Bias coefficients showed that none of the measurements differed significantly between the two settings (bias for GLS_endo = - 0.07 ± 2.94, p = 0.91; GLS_mid = 0.02 ± 2.70, p = 0.98, GLS_epi = 0.07 ± 2.53, p = 0.90). Coefficients of variation were as follows: GLS_endo = 15.11%, GLS_mid = 15.28%, GLS_epi = 17.26%, systolic strain rate = 15.66%, early diastolic strain rate = 38.46%, late diastolic strain rate = 11%. Changing between transducer frequency settings does not systematically derange speckle tracking measures. One can safely reduce the transducer frequency without compromising the validity of speckle tracking derived measures.