Simon Ray

Intensive lipid lowering with simvastatin and ezetimibe in aortic stenosis.

BACKGROUND Hyperlipidemia has been suggested as a risk factor for stenosis of the aortic valve, but lipid-lowering studies have had conflicting results. METHODS We conducted a randomized, double-blind trial involving 1873 patients with mild-to-moderate, asymptomatic aortic stenosis. The patients received either 40 mg of simvastatin plus 10 mg of ezetimibe or placebo daily. The primary outcome was a composite of major cardiovascular events, including death from cardiovascular causes, aortic-valve replacement, nonfatal myocardial infarction, hospitalization for unstable angina pectoris, heart failure, coronary-artery bypass grafting, percutaneous coronary intervention, and nonhemorrhagic stroke. Secondary outcomes were events related to aortic-valve stenosis and ischemic cardiovascular events. RESULTS During a median follow-up of 52.2 months, the primary outcome occurred in 333 patients (35.3%) in the simvastatin-ezetimibe group and in 355 patients (38.2%) in the placebo group (hazard ratio in the simvastatin-ezetimibe group, 0.96; 95% confidence interval [CI], 0.83 to 1.12; P=0.59). Aortic-valve replacement was performed in 267 patients (28.3%) in the simvastatin-ezetimibe group and in 278 patients (29.9%) in the placebo group (hazard ratio, 1.00; 95% CI, 0.84 to 1.18; P=0.97). Fewer patients had ischemic cardiovascular events in the simvastatin-ezetimibe group (148 patients) than in the placebo group (187 patients) (hazard ratio, 0.78; 95% CI, 0.63 to 0.97; P=0.02), mainly because of the smaller number of patients who underwent coronary-artery bypass grafting. Cancer occurred more frequently in the simvastatin-ezetimibe group (105 vs. 70, P=0.01). CONCLUSIONS Simvastatin and ezetimibe did not reduce the composite outcome of combined aortic-valve events and ischemic events in patients with aortic stenosis. Such therapy reduced the incidence of ischemic cardiovascular events but not events related to aortic-valve stenosis. (ClinicalTrials.gov number, NCT00092677.)

Myocardial viability as a determinant of the ejection fraction response to Carvedilol in patients with heart failure (CHRISTMAS trial): randomised controlled trial

BACKGROUND The improvement in left-ventricular ejection fraction (LVEF) in response to beta blockers is heterogeneous in patients with heart failure due to ischaemic heart disease, possibly indicating variations in the myocardial substrate underlying left-ventricular dysfunction. We investigated whether improvement in LVEF was associated with the volume of hibernating myocardium (viable myocardium with contractile failure). METHODS We did a double-blind, randomised trial to compare placebo and carvedilol for 6 months in individuals with stable, chronic heart failure due to ischaemic left-ventricular systolic dysfunction. We enrolled 489 patients, of whom 387 were randomised. Patients were designated hibernators or non-hibernators according to the volume of hibernating myocardium. The primary endpoint was change in LVEF, measured by radionuclide ventriculography, in hibernators versus non-hibernators, on carvedilol compared with placebo. Analysis was by intention to treat. RESULTS 82 patients dropped out of the study because of adverse events, withdrawal of consent, or failure to complete the investigation. Thus, 305 (79%) were analysed. LVEF was unchanged with placebo (mean change -0.4 [SE 0.9] and -0.4 [0.8] for non-hibernators and hibernators, respectively) but increased with carvedilol (2.5 [0.9] and 3.2 [0.8], respectively; p<0.0001 compared with baseline). Mean placebo-subtracted change in LVEF was 3.2% (95% CI 1.8-4.7; p=0.0001) overall, and 2.9% (0.7-5.1; p=0.011) and 3.6% (1.7-5.4; p=0.0002) in non-hibernators and hibernators, respectively. Effect of hibernator status on response of LVEF to carvedilol was not significant (0.7 [-2.2 to 3.5]; p=0.644). However, patients with more myocardium affected by hibernation or by hibernation and ischaemia had a greater increase in LVEF on carvedilol (p=0.0002 and p=0.009, respectively). INTERPRETATION Some of the effect of carvedilol on LVEF might be mediated by improved function of hibernating or ischaemic myocardium, or both. Medical treatment might be an important adjunct or alternative to revascularisation for patients with hibernating myocardium.

Outcome of Patients With Low-Gradient “Severe” Aortic Stenosis and Preserved Ejection Fraction

Background— Retrospective studies have suggested that patients with a low transvalvular gradient in the presence of an aortic valve area <1.0 cm2 and normal ejection fraction may represent a subgroup with an advanced stage of aortic valve disease, reduced stroke volume, and poor prognosis requiring early surgery. We therefore evaluated the outcome of patients with low-gradient “severe” stenosis (defined as aortic valve area <1.0 cm2 and mean gradient ⩽40 mm Hg) in the prospective Simvastatin and Ezetimibe in Aortic Stenosis (SEAS) study. Methods and Results— Outcome in patients with low-gradient “severe” aortic stenosis was compared with outcome in patients with moderate stenosis (aortic valve area 1.0 to 1.5 cm2; mean gradient 25 to 40 mm Hg). The primary end point of aortic valve events included death from cardiovascular causes, aortic valve replacement, and heart failure due to aortic stenosis. Secondary end points were major cardiovascular events and cardiovascular death. In 1525 asymptomatic patients (mean age, 67±10 years; ejection fraction, ≥55%), baseline echocardiography revealed low-gradient severe stenosis in 435 patients (29%) and moderate stenosis in 184 (12%). Left ventricular mass was lower in patients with low-gradient severe stenosis than in those with moderate stenosis (182±64 versus 212±68 g; P<0.01). During 46 months of follow-up, aortic valve events occurred in 48.5% versus 44.6%, respectively (P=0.37; major cardiovascular events, 50.9% versus 48.5%, P=0.58; cardiovascular death, 7.8% versus 4.9%, P=0.19). Low-gradient severe stenosis patients with reduced stroke volume index (⩽35 mL/m2; n=223) had aortic valve events comparable to those in patients with normal stroke volume index (46.2% versus 50.9%; P=0.53). Conclusions— Patients with low-gradient “severe” aortic stenosis and normal ejection fraction have an outcome similar to that in patients with moderate stenosis.

Outcome of Patients With Low-Gradient “Severe” Aortic Stenosis and Preserved Ejection Fraction The Heart Strategies Concentrating on Risk Evaluation (Heart SCORE) Study

Background— Retrospective studies have suggested that patients with a low transvalvular gradient in the presence of an aortic valve area <1.0 cm2 and normal ejection fraction may represent a subgroup with an advanced stage of aortic valve disease, reduced stroke volume, and poor prognosis requiring early surgery. We therefore evaluated the outcome of patients with low-gradient “severe” stenosis (defined as aortic valve area <1.0 cm2 and mean gradient ⩽40 mm Hg) in the prospective Simvastatin and Ezetimibe in Aortic Stenosis (SEAS) study. Methods and Results— Outcome in patients with low-gradient “severe” aortic stenosis was compared with outcome in patients with moderate stenosis (aortic valve area 1.0 to 1.5 cm2; mean gradient 25 to 40 mm Hg). The primary end point of aortic valve events included death from cardiovascular causes, aortic valve replacement, and heart failure due to aortic stenosis. Secondary end points were major cardiovascular events and cardiovascular death. In 1525 asymptomatic patients (mean age, 67±10 years; ejection fraction, ≥55%), baseline echocardiography revealed low-gradient severe stenosis in 435 patients (29%) and moderate stenosis in 184 (12%). Left ventricular mass was lower in patients with low-gradient severe stenosis than in those with moderate stenosis (182±64 versus 212±68 g; P<0.01). During 46 months of follow-up, aortic valve events occurred in 48.5% versus 44.6%, respectively (P=0.37; major cardiovascular events, 50.9% versus 48.5%, P=0.58; cardiovascular death, 7.8% versus 4.9%, P=0.19). Low-gradient severe stenosis patients with reduced stroke volume index (⩽35 mL/m2; n=223) had aortic valve events comparable to those in patients with normal stroke volume index (46.2% versus 50.9%; P=0.53). Conclusions— Patients with low-gradient “severe” aortic stenosis and normal ejection fraction have an outcome similar to that in patients with moderate stenosis.

Low-Flow Aortic Stenosis in Asymptomatic Patients: Valvular–Arterial Impedance and Systolic Function From the SEAS Substudy

OBJECTIVES This study sought to assess the impact of valvuloarterial impedance on left ventricular (LV) myocardial systolic function in asymptomatic aortic valve stenosis (AS). BACKGROUND In atherosclerotic AS, LV global load consists of combined valvular and arterial resistance to LV ejection. Global load significantly impacts LV ejection fraction (EF) in symptomatic AS, but less is known about its effect on LV myocardial function in asymptomatic AS. METHODS Echocardiograms in 1,591 patients with asymptomatic AS (67 +/- 10 years, 51% hypertensive) at baseline in the SEAS (Simvastatin Ezetimibe in Aortic Stenosis) study evaluating placebo-controlled combined simvastatin and ezetimibe treatment in AS were used to assess LV global load as valvuloarterial impedance and LV myocardial function as stress-corrected midwall shortening. The study population was divided into tertiles of global load. Stress-corrected midwall shortening was considered low if <87% in men and <90% in women. Low-flow AS was defined as stroke volume index <22 ml/m(2.04). RESULTS Energy loss index decreased (0.85 cm(2)/m(2) vs. 0.77 and 0.75 cm(2)/m(2)) and the prevalence of low stress-corrected midwall shortening increased (10% vs. 26% and 63%) with increasing LV global load (all p < 0.001). The EF was low in only 2% of patients. Patients with low-flow AS had higher LV global load and more often low midwall shortening than those with normal-flow AS (9.66 +/- 2.23 mm Hg/ml.m(2.04) and 77%, vs. 6.38 +/- 2.04 mm Hg/ml.m(2.04) and 30%, respectively, p < 0.001). In logistic regression analysis, LV global load was a main predictor of low stress-corrected midwall shortening independent of male sex, concentric LV geometry, LV hypertrophy (all p < 0.001), concomitant hypertension, and aortic regurgitation. CONCLUSIONS LV global load impacts LV myocardial function in asymptomatic AS independent of other main covariates of LV systolic function. LV myocardial systolic dysfunction is common in asymptomatic AS in particular in patients with low-flow AS and increased valvuloarterial afterload, whereas EF is generally preserved. (An Investigational Drug on Clinical Outcomes in Patients With Aortic Stenosis [Narrowing of the Major Blood Vessel of the Heart]; NCT00092677).

Comprehensive Validation of Cardiovascular Magnetic Resonance Techniques for the Assessment of Myocardial Extracellular Volume

Background— Extracellular matrix expansion is a key element of ventricular remodeling and a potential therapeutic target. Cardiovascular magnetic resonance (CMR) T1-mapping techniques are increasingly used to evaluate myocardial extracellular volume (ECV); however, the most widely applied methods are without histological validation. Our aim was to perform comprehensive validation of (1) dynamic-equilibrium CMR (DynEq-CMR), where ECV is quantified using hematocrit-adjusted myocardial and blood T1 values measured before and after gadolinium bolus; and (2) isolated measurement of myocardial T1, used as an ECV surrogate. Methods and Results— Whole-heart histological validation was performed using 96 tissue samples, analyzed for picrosirius red collagen volume fraction, obtained from each of 16 segments of the explanted hearts of 6 patients undergoing heart transplantation who had prospectively undergone CMR before transplantation (median interval between CMR and transplantation, 29 days). DynEq-CMR–derived ECV was calculated from T1 measurements made using a modified Look-Locker inversion recovery sequence before and 10 and 15 minutes post contrast. In addition, ECV was measured 2 to 20 minutes post contrast in 30 healthy volunteers. There was a strong linear relationship between DynEq-CMR–derived ECV and histological collagen volume fraction (P<0.001; within-subject: r=0.745; P<0.001; r 2=0.555 and between-subject: r=0.945; P<0.01; r 2=0.893; for ECV calculated using 15-minute postcontrast T1). Correlation was maintained throughout the entire heart. Isolated postcontrast T1 measurement showed significant within-subject correlation with histological collagen volume fraction (r=−0.741; P<0.001; r 2=0.550 for 15-minute postcontrast T1), but between-subject correlations were not significant. DynEq-CMR–derived ECV varied significantly according to contrast dose, myocardial region, and sex. Conclusions— DynEq-CMR–derived ECV shows a good correlation with histological collagen volume fraction throughout the whole heart. Isolated postcontrast T1 measurement is insufficient for ECV assessment.

Mitral repair best practice: proposed standards

Objectives: To define best practice standards for mitral valve repair surgery. Design: Development of standards for process and outcome by consensus. Setting: Multidisciplinary panel of surgeons, anaesthetists, and cardiologists with interests and expertise in caring for patients with severe mitral regurgitation. Main outcome measures: Standards for best practice were defined including the full spectrum of multidisciplinary aspects of care. Results: 19 criteria for best practice were defined including recommendations on surgical training, intraoperative transoesophageal echocardiography, surgery for atrial fibrillation, audit, and cardiology and imaging issues. Conclusions: Standards for best practice in mitral valve repair were defined by multidisciplinary consensus. This study gives centres undertaking mitral valve repair an opportunity to benchmark their care against agreed standards that are challenging but achievable. Working towards these standards should act as a stimulus towards improvements in care.

Aortic valve surgery: Marked increases in volume and significant decreases in mechanical valve use—an analysis of 41,227 patients over 5 years from the Society for Cardiothoracic Surgery in Great Britain and Ireland National database

OBJECTIVES Aortic valve replacement is accepted as a standard treatment for aortic stenosis and regurgitation. To help plan the national requirement for conventional and catheter-based procedures, we have analyzed the Society for Cardiothoracic Surgery in Great Britain and Ireland audit database to look at changes in practice over time. METHODS All patients undergoing conventional aortic valve replacement with or without coronary artery surgery from April 2004 to March 2009 were included. The main outcome measures were changes in the number, characteristics, operative details, and in-hospital mortality. We have looked particularly at trends and outcomes in elderly and high-risk patients (EuroSCORE of 10 or more) who may now be considered for percutaneous aortic valve insertion. RESULTS A total of 41,227 patients underwent aortic valve surgery over 5 years with an in-hospital mortality of 4.1%. The annual number increased from 7396 in 2004-2005 to 9333 in 2008-2009, with significant increases (P < .0005) in mean age (68.8-70.2 years), the proportion of patients with aortic stenosis (62.4%-65.1%), octogenarians (13.6%-18.4%), high-risk patients (24.6%-27.7%), and those receiving biological valves (65.4%-77.8%). The incidence of permanent cerebrovascular accident was 1.2% and 1.0% in patients having only an aortic valve replacement. The dialysis rate was 4.5% and the reoperation rate for bleeding was 6.6%. Overall mortality decreased from 4.4% in 2004-2005 to 3.7% in 2008-2009. Survival to a mean follow-up of 2.5 years was 89%. CONCLUSIONS We have seen a large increase in annual volume of aortic valve replacements, with more patients undergoing surgery for aortic stenosis and an increase in surgery in the elderly and high-risk patients.

Left ventricular torsion in primary chronic mitral regurgitation

Background: Torsion is essential for normal systolic and diastolic function of the left ventricle (LV), and is known to be abnormal in animal models of mitral regurgitation (MR). There are no comparable data in humans. Objectives: To study LV torsion in humans with chronic primary MR using speckle-tracking echocardiography. Methods: Rotation and rotation rate were measured from two-dimensional (2D) greyscale LV base and apex short-axis images by speckle-tracking echocardiography in 38 patients and 30 controls. Using custom software, plots of torsion against time were constructed by deducting base rotation from apex rotation. Loops of torsion against LV radial/longitudinal displacement and volume were automatically plotted. Results: Peak systolic torsion, systolic torsional velocity and untwisting velocity were similar in the two groups. In controls, untwisting started 23 ms before aortic valve closure but was delayed in MR to 15 ms after aortic valve closure, p<0.001. In normal subjects there was rapid untwisting during isovolumic relaxation, with minimal expansion of the LV radial and longitudinal axes. In MR, early untwisting rate was decreased, with less untwisting for a given volume increase. Extensive LV remodelling and worsening MR were associated with progressive reductions in systolic torsion and untwisting velocity, and progressive delay in the onset of untwisting. Conclusions: Chronic MR results in significant delay and slowing of LV untwisting, such that early untwisting is coupled with chamber expansion. Correlations between disease severity and torsional parameters suggest a potential role of these variables in assessing early signs of ventricular dysfunction.

Impact of Pressure Recovery on Echocardiographic Assessment of Asymptomatic Aortic Stenosis: A SEAS Substudy

OBJECTIVES The aim of this analysis was to assess the diagnostic importance of pressure recovery in evaluation of aortic stenosis (AS) severity. BACKGROUND Although pressure recovery has previously been demonstrated to be particularly important in assessment of AS severity in groups of patients with moderate AS or small aortic roots, it has never been evaluated in a large clinical patient cohort. METHODS Data from 1,563 patients in the SEAS (Simvastatin and Ezetimibe in Aortic Stenosis) study was used. Inner aortic diameter was measured at annulus, sinus, sinotubular junction, and supracoronary level. Aortic valve area index (AVAI) was calculated by continuity equation and pressure recovery and pressure recovery adjusted AVAI (energy loss index [ELI]), by validated equations. Primarily, sinotubular junction diameter was used to calculate pressure recovery and ELI, but pressure recovery and ELI calculated at different aortic root levels were compared. Severe AS was identified as AVAI and ELI < or =0.6 cm(2)/m(2). Patients were grouped into tertiles of peak transaortic velocity. RESULTS Pressure recovery increased with increasing peak transaortic velocity. Overestimation of AS severity by unadjusted AVAI was largest in the lowest tertile and if pressure recovery was assessed at the sinotubular junction. In multivariate analysis, a larger difference between AVAI and ELI was associated with lower peak transaortic velocity (beta = 0.35) independent of higher left ventricular ejection fraction (beta = -0.049), male sex (beta = -0.075), younger age (beta = 0.093), and smaller aortic sinus diameter (beta = 0.233) (multiple R(2) = 0.18, p < 0.001). Overall, 47.5% of patients classified as having severe AS by AVAI were reclassified to nonsevere AS when pressure recovery was taken into account. CONCLUSIONS For accurate assessment of AS severity, pressure recovery adjustment of AVA must be routinely performed. Estimation of pressure recovery at the sinotubular junction is suggested.