Grewal, Jasmine

Limited information exists regarding the echocardiographic and clinical predictors of exercise capacity and their effects on exercise with advancing age or by sex. We hypothesized that LV diastolic function (DF) impacts exercise capacity to a greater degree with advancing age. This was a prospective cohort study of consecutive patients undergoing routine exercise echocardiography with the Bruce protocol (n=2955). DF assessments at rest and exercise were performed. Those with echocardiographic exercise-induced ischemia and significant valvular disease were excluded. Univariate and multivariate analyses were conducted to determine the strongest echocardiographic and clinical predictors of exercise capacity (METs). Results were reported as unstandardized β coefficient (Standard Error) as outlined beside each variable. Age and sex interactions of these predictors with exercise capacity were determined. The strongest independent multivariate predictors of exercise capacity were female vs. male sex [−1.98 (0.07), p<0.0001], body mass index >30 kg/m 2 [−1.24 (0.08), p<0.0001], age per 10 year increment [−0.85 (0.01), p<0.0001], mild resting diastolic dysfunction vs. normal [−0.70 (0.10), p<0.0001], and moderate/severe resting diastolic dysfunction vs. normal [−1.3 (0.13), p<0.0001]. LV filling pressures measured by a resting E/e’ ≥ 15 [−0.42 (0.14), p=0.004] or exercise E/e’≥ 15 [−0.31 (0.14), p<0.0001] similarly predicted a reduction in exercise capacity, each in separate multivariate analyses. The impact of impaired relaxation and left ventricular filling pressures on exercise capacity increased with advancing age (p<0.001 and p=0.02 respectively), and was most marked after age 50. These predictors had a similar negative effect on exercise capacity among men and women (p=NS). In conclusion, in this large population referred for exercise echocardiography and not limited by ischemia, resting DF and resting/exercise LV filling pressures independently predicted exercise capacity. The increasingly potent effect of impaired relaxation and exercise LV filling pressures with advancing age suggest that DF plays an important role in the development of exercise intolerance in the elderly.

Objectives Women with Turner syndrome (TS) are frequently counselled against pregnancy due to lack of data and unclear aortic dissection risk. However, with advances in fertility therapy, more women with TS are contemplating pregnancy. This study compared rates of adverse cardiovascular (CV) outcomes among: (1) pregnant and non-pregnant women with TS and (2) pregnant women with TS with/without structural heart disease. Methods Retrospective analysis of pregnant and age-matched non-pregnant controls with TS (2005–2017) across 10 CV centres was done. Data were collected at initial evaluation in pregnancy and outcomes were assessed to 6 months postpartum. Adverse CV events were defined as CV death, aortic dissection/rupture and/or aortic intervention. Non-pregnant age-matched controls were followed over the same time period. Results Sixty-eight pregnancies were included (60 women, mean age 33 years, 48% primigravid, 49% fertility therapy, 80% structurally normal heart, 25% XO karyotype). Based on American Society of Reproductive Medicine criteria, 10 pregnancies occurred in women stratified to high-risk category. There were no CV events in the pregnant women or in the non-pregnant women with TS. Obstetric events complicated 12 (18%) pregnancies with 9 (13%) attributed to hypertensive disorder of pregnancy. Fetal events included small for gestational age neonates (18%), preterm delivery (15%) and fetal death (3%). Conclusions This study helps to refine the approach to pregnancy in women with TS. Among women with TS without structural heart disease, pregnancy does not impose an increased risk of CV outcomes. Among women with TS with structural heart disease, the risk of pregnancy is not as prohibitive as previously described but does require ongoing evaluation.

Background— Mitral annulus is a complex structure of poorly understood physiology. Full-volume real-time 3-dimensional transesophageal echocardiography offers a unique opportunity to completely image and quantify mitral annulus size and motion. Methods and Results— Real-time 3-dimensional transesophageal echocardiography of the mitral valve was acquired in 32 patients with myxomatous valve disease (MVD) and moderate to severe regurgitation, 15 normal control subjects, and 10 patients with ischemic mitral regurgitation of identical body surface area. Mitral annular dimensions (circumference, area, anteroposterior and intercommissural diameters, height, and ratio of height to intercommissural diameter ratio, which appraises annular saddle-shape depth) were measured throughout the cardiac cycle with dedicated quantification software. Compared with direct surgical measurement, 3-dimensional anterior annular dimension provided reliable measurements (mean difference, 0.1±0.1 mm; P =0.73; 95% confidence interval, ±4.4 mm). Annular dimensions were larger in MVD patients compared with control subjects in diastole (all P <0.05). Normal annulus displayed early-systolic anteroposterior ( P <0.001) and area ( P =0.04) contraction, increased height ( P <0.001), and deeper saddle shape (ratio of height to intercommissural diameter, 15±1% to 21±1%; P <0.001), whereas intercommissural diameter was unchanged ( P =0.30). In contrast, MVD showed early-systolic intercommissural dilatation ( P =0.02) and no area contraction ( P =0.99), height increase ( P =0.11), or saddle-shape deepening ( P =0.35). Late-systolic MVD annular saddle shape deepened but annular area excessively enlarged ( P <0.04) as a result of persistent intercommissural widening ( P <0.02). MVD annulus also contrasts with ischemic mitral regurgitation annulus, which, despite similar anteroposterior enlargement, is narrower and essentially adynamic. After MVD repair, the annulus remained dynamic without systolic saddle-shape accentuation ( P =0.30). Conclusions— Real-time 3-dimensional transesophageal echocardiography provides insights into normal, dynamic mitral annulus function with early-systolic area contraction and saddle-shape deepening contributing to mitral competency. MVD annulus is also dynamic but considerably different with loss of early-systolic area contraction and saddle-shape deepening despite similar magnitude of ventricular contraction, suggestive of ventricular-annular decoupling. Subsequent area enlargement may contribute to mitral incompetence. After mitral repair, MVD annulus remains dynamic without systolic saddle-shape accentuation. Thus, real-time 3-dimensional transesophageal echocardiography provides new insights that allow the refining of mitral pathophysiology concepts and repair strategies.

Although several studies have examined the cardiac functional determinants of exercise capacity, few have investigated the effects of structural remodeling. The current study evaluated the association between cardiac geometry and exercise capacity. Subjects with ejection fraction ≥50% and no valvular disease, myocardial ischemia, or arrhythmias were identified from a large prospective exercise echocardiography database. Left ventricular mass index and relative wall thickness were used to classify geometry into normal, concentric remodeling, eccentric hypertrophy, and concentric hypertrophy. All of the subjects underwent symptom-limited treadmill exercise according to standard Bruce protocol. Maximal exercise tolerance was measured in metabolic equivalents. Of 366 (60±14 years; 57% male) subjects, 166 (45%) had normal geometry, 106 (29%) had concentric remodeling, 40 (11%) had eccentric hypertrophy, and 54 (15%) had concentric hypertrophy. Geometry was related to exercise capacity: in descending order, the maximum achieved metabolic equivalents were 9.9±2.8 in normal, 8.9±2.6 in concentric remodeling, 8.6±3.1 in eccentric hypertrophy, and 8.0±2.7 in concentric hypertrophy (all P <0.02 versus normal). Left ventricular mass index and relative wall thickness were negatively correlated with exercise tolerance in metabolic equivalents ( r =−0.14; P =0.009 and r =−0.21; P <0.001, respectively). Augmentation of heart rate and ejection fraction with exercise were blunted in concentric hypertrophy compared with normal, even after adjusting for medications. In conclusion, the pattern of ventricular remodeling is related to exercise capacity among low-risk adults. Subjects with concentric hypertrophy display the greatest limitation, and this is related to reduced systolic and chronotropic reserve. Reverse remodeling strategies may prevent or treat functional decline in patients with structural heart disease.