Surgical outcome of discrete subaortic stenosis in adults: a multicenter study.

BACKGROUND: Discrete subaortic stenosis is notable for its unpredictable hemodynamic progression in childhood and high reoperation rate; however, data about adulthood are scarce. METHODS AND RESULTS: Adult patients who previously underwent surgery for discrete subaortic stenosis were included in this retrospective multicenter cohort study. Mixed-effects and joint models were used to assess the postoperative progression of discrete subaortic stenosis and aortic regurgitation, as well as reoperation. A total of 313 patients at 4 centers were included (age at baseline, 20.2 years [25th-75th percentile, 18.4-31.0 years]; 52% male). Median follow-up duration was 12.9 years (25th-75th percentile, 6.2-20.1 years), yielding 5617 patient-years. The peak instantaneous left ventricular outflow tract gradient decreased from 75.7±28.0 mm Hg preoperatively to 15.1±14.1 mm Hg postoperatively (P<0.001) and thereafter increased over time at a rate of 1.31±0.16 mm Hg/y (P=0.001). Mild aortic regurgitation was present in 68% but generally did not progress over time (P=0.76). A preoperative left ventricular outflow tract gradient ≥80 mm Hg was a predictor for progression to moderate aortic regurgitation postoperatively. Eighty patients required at least 1 reoperation (1.8% per patient-year). Predictors for reoperation included female sex (hazard ratio, 1.53; 95% confidence interval, 1.02-2.30) and left ventricular outflow tract gradient progression (hazard ratio, 1.45; 95% confidence interval, 1.31-1.62). Additional myectomy did not reduce the risk for reoperation (P=0.92) but significantly increased the risk of a complete heart block requiring pacemaker implantation (8.1% versus 1.7%; P=0.005). CONCLUSIONS: Survival is excellent after surgery for discrete subaortic stenosis; however, reoperation for recurrent discrete subaortic stenosis is not uncommon. Over time, the left ventricular outflow tract gradient slowly increases and mild aortic regurgitation is common, although generally nonprogressive over time. Myectomy does not show additional advantages, and because it is associated with an increased risk of complete heart block, it should not be performed routinely.

Natural history of discrete subaortic stenosisin adults: a multicentre study.

AIMS: Discrete subaortic stenosis (DSS) is often diagnosed early in life and known for its sometimes rapid haemodynamic progression in childhood and strong association with aortic regurgitation (AR). However, data about the evolution of DSS in adulthood are scarce. Therefore, we aimed to evaluate the natural history of DSS, and identify risk factors for the progression of DSS, AR, and intervention-free survival. METHODS AND RESULTS: Conservatively managed adult DSS patients were included in this retrospective multicentre cohort study. Mixed-effects and joint models were used to assess the progression of DSS and AR, and intervention-free survival. Longitudinal natural history data were available for 149 patients [age 20 (IQR: 18-34) years, 48% male]. Sixty patients (40.3%) had associated congenital heart defects (CHDs). The median follow-up duration was 6.3 (IQR: 3.0-12.4) years. The baseline peak left ventricular outflow tract (LVOT) gradient was 32.3 ± 17.0 mmHg and increased by 0.8 ± 0.1 mmHg/year. While the baseline LVOT gradient (P = 0.891) or age (P = 0.421) did not influence the progression rate, the presence of associated CHD was associated with faster progression (P = 0.005). Mild AR was common (58%), but did not significantly progress over time (P = 0.701). The median intervention-free survival was 16 years and associated with the baseline LVOT gradient [hazard ratio (HR) = 3.9 (95% CI: 2.0-7.6)], DSS progression [HR = 2.6 (95% CI: 2.0-3.5)], and AR [HR = 6.4 (95% CI 2.6-15.6)]. CONCLUSION: In contrast to children, DSS progresses slowly in adulthood. In particular, patients with associated CHD are at risk for faster progression and should be monitored cautiously. Discrete subaortic stenosis progression is not influenced by the baseline LVOT gradient or age. Mild AR is common, but non-progressive over time.

Assessment of subendocardial contractile function in aortic stenosis: a study using speckle tracking echocardiography.

BACKGROUND: Angina and an electrocardiographic strain pattern are potential manifestations of subendocardial ischemia in aortic stenosis (AS). Left ventricular (LV) twist is known to increase proportionally to the severity of AS, which may be a result of loss of the inhibiting effect of the subendocardial fibers due to subendocardial dysfunction. It has also been shown that the ratio of LV twist to circumferential shortening of the endocardium (twist-to-shortening ratio [TSR]) is a reliable parameter of subendocardial dysfunction. The aim of this study was to investigate whether these markers are increased in AS patients with angina and/or electrocardiographic strain. METHODS: The study comprised 60 AS patients with an aortic valve area <2.0 cm(2) and LV ejection fraction >50%, and 30 healthy-for age and gender matched-control subjects. LV rotation parameters were determined by speckle tracking echocardiography. RESULTS: Comparison of patients without angina and strain (n = 22), with either angina or strain (n = 28), and with both angina and strain (n = 8), showed highest peak systolic LV apical rotation, peak systolic LV twist, and TSR, in patients with more signs of subendocardial ischemia. In a multivariate linear regression model, only severity of AS and the presence of angina and/or strain could be identified as independent predictors of peak systolic LV twist and TSR. CONCLUSIONS: Peak systolic LV twist and TSR are increased in AS patients and related to the severity of AS and symptoms (angina) or electrocardiographic signs (strain) compatible with subendocardial ischemia.

Progression of aortic valve stenosis in adults: a systematic review.

BACKGROUND AND AIM OF THE STUDY: Published reports on the progression of aortic valve stenosis (AS) over time are usually small, with widely varying AS progression rate estimates. Reliable estimates of AS progression are important for surveillance scheduling and optimal timing of surgical or interventional treatment. This systematic review presents an overview of published evidence on AS progression over time in adult patients with AS. METHODS: A systematic review using PubMed and Embase was performed to assess AS progression over time in adult patients with AS measured by echocardiography. A total of 27 reports (15 prospective, 12 retrospective, total 4,921 patients, pooled age 69 years) was included in which the baseline and progression rates of the hemodynamic variables were pooled. Subgroup analyses were performed to investigate factors associated with AS progression and sources of heterogeneity. RESULTS: Pooled annual AS progression was 3.70 mmHg per year (SE = 0.10) for randomized controlled trials, and 6.03 mmHg per year (SE = 0.10) for observational studies. A large variability in observed AS progression was found between studies, as well as a wide variety of methods employed to measure AS. CONCLUSION: The observed large individual variability in measuring AS progression among the selected studies calls for the implementation of a universal method of AS assessment. This will facilitate an insight into the determinants of AS progression and allow for an evidence-based tailoring of treatment.

Outcome after aortic valve replacement in children: A systematic review and meta-analysis.

OBJECTIVE: Despite an increasing interest in pediatric aortic valve repair, aortic valve replacement in children may be unavoidable. The evidence on outcome after pediatric aortic valve replacement is limited and usually reported in small case series. This systematic review and meta-analysis aims to provide an overview of reported outcome of pediatric patients after aortic valve replacement. METHODS: A systematic literature search for publications reporting outcome after pediatric aortic valve replacement published between January 1990 and May 2015 was conducted. Studies written in English with a study size of more than 30 patients were included. RESULTS: Thirty-four publications reporting on 42 cohorts were included in this review: 26 concerning the Ross procedure (n = 2409), 13 concerning mechanical prosthesis aortic valve replacement (n = 696), and 3 concerning homograft aortic valve replacement (n = 224). There were no studies on bioprostheses that met our inclusion criteria. The pooled mean patient age was 9.4 years, 12.8 years, and 8.9 years for Ross, mechanical prosthesis, and homograft recipients, respectively. Pooled mean follow-up was 6.6 years. The Ross procedure was associated with lower early (4.20%; 95% confidence interval [CI], 3.37-5.22 vs 7.34%; 95% CI, 5.21-10.34 vs 12.82%; 95% CI, 8.91-18.46) and late mortality (0.64%/y; 95% CI, 0.49-0.84 vs 1.23%/y; 95% CI, 0.85-1.79 vs 1.59%/y; 95% CI, 1.03-2.46) compared with mechanical prosthesis aortic valve replacement and homograft aortic valve replacement, respectively. No significantly different aortic valve reoperation rates were observed between the Ross procedure and mechanical prosthesis aortic valve replacement (1.60%/y; 95% CI, 1.27-2.02 vs 1.07%/y; 95% CI, 0.68-1.68, respectively), whereas homograft aortic valve replacement was associated with significantly higher aortic valve reoperation rates (5.44%/y; 95% CI, 4.24-6.98). The Ross procedure-associated right ventricular outflow tract reoperation rate was 1.91% per year (95% CI, 1.50-2.44). CONCLUSIONS: This systematic review illustrates that all currently available aortic valve substitutes are associated with suboptimal results in children, reflecting the urgent need for reliable and durable repair techniques and innovative replacement solutions for this challenging group of patients.

Pregnancy outcomes in women with aortic valve substitutes.

Young women who require aortic valve replacement need information on the potential cardiac and obstetric complications of pregnancy for the different valve substitutes available. We, therefore, assessed the pregnancy outcomes in women who had received an autograft, homograft, or mechanical valve in the aortic position. Women who were pregnant after surviving aortic valve replacement at our institution from 1987 to 2011 were included. Information on cardiac status and pregnancy outcome was obtained through the hospital medical records and by an extensive patient questionnaire. A total of 40 women experienced 67 pregnancies, of which 55 (82%) were completed pregnancies, 6 (9%) were miscarriages, and 6 (9%) were terminated. Of the 40 women, 18 (45%) had a pulmonary autograft, 13 (32%) a homograft, and 9 (23%) a mechanical valve. The mean age at the first pregnancy was 30.0 ± 5.7 years. No maternal mortality but 1 fetal death (1.8%) and 1 neonatal death (1.8%) occurred. Maternal cardiac complications developed in 13% and obstetric complications in 38% of the completed pregnancies. Heart failure (9%), arrhythmias (7%), hypertension-related disorders (7%), preterm delivery (24%), and small-for-gestational-age infants (15%) were most often encountered. Mechanical valve recipients had the greatest incidence of both cardiac and obstetric complications. In conclusion, pregnancy-associated complications after aortic valve replacement were common, and human tissue valves should be considered in the discussion for the optimal aortic valve substitute in a young woman. However, careful obstetric monitoring is mandatory.

Left ventricular twist and untwist in aortic stenosis.

BACKGROUND: To optimally exploit the potential added diagnostic and prognostic value of new left ventricular (LV) deformation parameters, better understanding of LV mechanics in aortic stenosis (AS) is warranted. We sought to determine a broad spectrum of LV rotation parameters in AS patients and age-matched healthy controls, in order to gain insight into the mechanical properties of the LV in AS. METHODS: The study comprised 48 AS patients with an aortic valve area<2.0 cm2 and LV ejection fraction>50%, and 24 healthy--for age and gender matched--control subjects. LV peak systolic rotation (Rotmax), LV peak systolic twist (Twistmax), untwisting rate (mean diastolic untwisting velocity from Twistmax to mitral valve opening), peak diastolic untwisting velocity, and time-to-peak diastolic untwisting velocity were determined by speckle tracking echocardiography. RESULTS: AS patients had normal basal Rotmax and increased apical Rotmax, resulting in increased Twistmax (13.4±4.0° vs. 11.4±2.7°, P<0.05). Apical Rotmax and Twistmax correlated significantly to echo-Doppler indicators of AS severity. Time-to-peak diastolic untwisting velocity was increased (20±10% vs. 15±9%, P<0.05) and untwisting rate was decreased (-38±21°/s vs. -50±28°/s, P<0.01) in AS patients. CONCLUSIONS: Twistmax increases proportionally to the severity of AS, which might serve as a compensatory mechanism to maintain systolic LV function. LV diastolic untwisting is delayed and the untwisting rate is reduced in AS.