Differences in Cardiac Remodeling in Left-Sided Valvular Regurgitation: Implications for Optimal Definition of Significant Aortic Regurgitation

BackgroundGrading of aortic regurgitation (AR) and mitral regurgitation (MR) is similar in the cardiology guidelines despite distinct differences in left ventricular (LV) adaptive pathophysiology.ObjectivesThis study compared differences in LV remodeling in patients with similar degrees of AR and MR severity and evaluated optimal cutoffs for significant AR in relation to the outcome of aortic valve replacement or repair (AVR) during follow-up.MethodsFrom 2008 to 2018, consecutive patients with isolated AR or MR who had cardiac magnetic resonance (CMR) were identified and CMR parameters were compared. Patients with left ventricular ejection fraction (LVEF) <50%, ischemic scar >5%, valve stenosis, or concomitant regurgitation were excluded. Patients were followed longitudinally for AVR.ResultsBaseline characteristics of isolated AR (n = 418) and isolated MR (n = 1,073) were comparable except for higher male proportion and hypertension in AR, while heart failure was more prevalent in MR. Indexed LV end-diastolic and end-systolic volumes and mass were higher in AR compared with MR at the same level of regurgitant fraction. During follow-up (mean 2.1 years), 18.7% of AR patients underwent AVR based on symptoms or LV remodeling. Interestingly, 38.0% of patients that underwent AVR within 3 months after CMR did not meet severe AVR by current guidelines of AR severity. AR regurgitant fraction>35% had high sensitivity (86%) and specificity (88%) for identifying patients who underwent AVR.ConclusionsFor similar regurgitation severity, LV remodeling is different in AR compared with MR. Cardiac symptoms and significant LV remodeling in AR requiring AVR occur frequently in patients with less severity than currently proposed. The study findings suggest that the optimal threshold for severe AR with CMR is different than MR and is lower than currently stated in the guidelines.     

Moderate Aortic Stenosis in Patients With Heart Failure and Reduced Ejection Fraction

BackgroundThe study investigators previously reported that moderate aortic stenosis (AS) is associated with a poor prognosis in patients with heart failure (HF) with reduced left ventricular ejection fraction (LVEF) (HFrEF). However, the respective contribution of moderate AS versus HFrEF to the outcomes of these patients is unknown.ObjectivesThis study sought to determine the impact of moderate AS on outcomes in patients with HFrEF.MethodsThe study included 262 patients with moderate AS (aortic valve area >1.0 and <1.5 cm²; and peak aortic jet velocity >2 and <4 m/s, at rest or after dobutamine stress echocardiography) and HFrEF (LVEF <50%). These patients were matched 1:1 for sex, age, estimated glomerular filtration rate, New York Heart Association functional class III to IV, presence of diabetes, LVEF, and body mass index with patients with HFrEF but no AS (i.e., peak aortic jet velocity <2 m/s). The endpoints were all-cause mortality and the composite of death and HF hospitalization.ResultsA total of 262 patients with HFrEF and moderate AS were matched with 262 patients with HFrEF and no AS. Mean follow-up was 2.9 ± 2.2 years. In the moderate AS group, mean aortic valve area was 1.2 ± 0.2 cm², and mean gradient was 14.5 ± 4.7 mm Hg. Moderate AS was associated with an increased risk of mortality (hazard ratio [HR]: 2.98; 95% confidence interval [CI]: 2.08 to 4.31; p < 0.0001) and of the composite of HF hospitalization and mortality (HR: 2.34; 95% CI: 1. 72 to 3.21; p < 0.0001). In the moderate AS group, aortic valve replacement (AVR) performed in 44 patients at a median follow-up time of 10.9 ± 16 months during follow-up was associated with improved survival (HR: 0.59; 95% CI: 0.35 to 0.98; p = 0.04). Notably, surgical AVR was not significantly associated with improved survival (p = 0.92), whereas transcatheter AVR was (HR: 0.43; 95% CI: 0.18 to 1.00; p = 0.05).ConclusionsIn this series of patients with HFrEF, moderate AS was associated with a marked incremental risk of mortality. AVR, and especially transcatheter AVR during follow-up, was associated with improved survival in patients with HFrEF and moderate AS. These findings provide support to the realization of a randomized trial to assess the effect of early transcatheter AVR in patients with HFrEF and moderate AS.     

Transcatheter Versus Surgical Aortic Valve Replacement in Patients With Rheumatic Aortic Stenosis

BackgroundPatients with rheumatic aortic stenosis (AS) were excluded from transcatheter aortic valve replacement (TAVR) trials.ObjectivesThe authors sought to examine outcomes with TAVR versus surgical aortic valve replacement (SAVR) in patients with rheumatic AS, and versus TAVR in nonrheumatic AS.MethodsThe authors identified Medicare beneficiaries who underwent TAVR or SAVR from October 2015 to December 2017, and then identified patients with rheumatic AS using prior validated International Classification of Diseases, Version 10 codes. Overlap propensity score weighting analysis was used to adjust for measured confounders. The primary study outcome was all-cause mortality. Multiple secondary outcomes were also examined.ResultsThe final study cohort included 1,159 patients with rheumatic AS who underwent aortic valve replacement (SAVR, n = 554; TAVR, n = 605), and 88,554 patients with nonrheumatic AS who underwent TAVR. Patients in the SAVR group were younger and with lower prevalence of most comorbidities and frailty scores. After median follow-up of 19 months (interquartile range: 13 to 26 months), there was no difference in all-cause mortality with TAVR versus SAVR (11.2 vs. 7.0 per 100 person-year; adjusted hazard ratio: 1.53; 95% confidence interval: 0.84 to 2.79; p = 0.2). Compared with TAVR in nonrheumatic AS, TAVR for rheumatic AS was associated with similar mortality (15.2 vs. 17.7 deaths per 100 person-years (adjusted hazard ratio: 0.87; 95% confidence interval: 0.68 to 1.09; p = 0.2) after median follow-up of 17 months (interquartile range: 11 to 24 months). None of the rheumatic TAVR patients, <11 SAVR patients, and 242 nonrheumatic TAVR patients underwent repeat aortic valve replacement (124 redo-TAVR and 118 SAVR) at follow-up.ConclusionsCompared with SAVR, TAVR could represent a viable and possibly durable option for patients with rheumatic AS.     

Prognosis of Severe Low-Flow,Low-Gradient Aortic Stenosis by Stroke Volume Index and Transvalvular Flow Rate

ObjectivesThis study determined whether flow state classified by stroke volume index (SVi) or transvalvular flow rate (FR) improved risk stratification of all-cause mortality, hospitalization due to heart failure, and aortic valvular interventions for patients with severe aortic stenosis (AS).BackgroundSVi is a widely accepted classification for flow state in severe low-flow, low-gradient (LFLG) AS. Recent studies suggest that FR more closely approximates true AS severity and provides more useful prognostication than SVi.MethodsPatients with severe AS over a 7-year period were subclassified by echocardiographic parameters. LFLG-AS was defined as severe AS (aortic valve area index [AVAi]: <0.6 cm²/m²), with a mean transvalvular pressure gradient of <40 mm Hg in the setting of low flow state: SVi of <35 ml/m² and/or FR of <200 ml/s and subclassified into preserved (≥50%; paradoxical) or reduced (<50%; classical) left ventricular ejection fraction (LVEF).ResultsAmong 621 consecutive patients with severe AS, the proportions of patients classified as LFLG-AS were different between SVi and FR (p < 0.001). Classification using SVi, FR, and LVEF was a strong predictor of the composite endpoint at the 2-year follow-up. The addition of SVi to the echocardiographic and clinical model provided significant improvement in reclassification (net reclassification improvement: 0.089; 95% confidence interval [CI]: 0.045 to 0.133; p = 0.04), whereas addition of FR did not (net reclassification improvement: 0.061; 95% CI: 0.016 to 0.106; p = 0.17). C-statistics indicated improved risk discrimination when AVAi, LVEF, and SVi or FR were added as predictive variables to the clinical model (p = 0.006).ConclusionsLow SVi or FR was associated with adverse cardiovascular events and showed improvement in discrimination, but only SVi, not FR, significantly improved risk reclassification compared to other conventional clinical and echocardiographic predictors. This suggests that FR is not superior to SVi in distinguishing true severe from pseudosevere forms of AS and identification of patients with LFLG-AS who have worse outcomes.     

Aortic Stenosis Progression,Cardiac Damage,and Survival: Comparison Between Bicuspid and Tricuspid Aortic Valves

ObjectivesThis study sought to compare aortic stenosis (AS) progression rates, AS-related cardiac damage (AS-CD) indicator incidence and determinants, and survival between patients with tricuspid aortic valve (TAV)-AS and those with bicuspid aortic valve (BAV)-AS.BackgroundDifferences in AS progression and AS-CD between patients with BAV and patients with TAV are unknown.MethodsWe retrospectively studied consecutive patients with baseline peak aortic valve velocity (peakV) ≥2.5 m/s and left ventricular ejection fraction ≥50%. Follow-up echocardiograms (n = 4,818) provided multiparametric AS progression rates and AS-CD.ResultsThe study included 330 BAV (age 54 ± 14 years) and 581 patients with TAV (age 72 ± 11 years). At last echocardiogram (median: 5.9 years; interquartile range: 3.9 to 8.5 years), BAV-AS exhibited similar peakV and mean pressure gradient (MPG) as TAV-AS, but larger calculated aortic valve area due to larger aortic annulus (p < 0.0001). Multiparametric progression rates were similar between BAV-AS and TAV-AS (all p ≥ 0.08) and did not predict age-/sex-adjusted survival (p ≥ 0.45). Independent determinants of rapid progression were male sex and baseline AS severity for TAV (all p ≤ 0.024), and age, baseline AS severity, and cardiac risk factors (age interaction: p = 0.02) for BAV (all p ≤ 0.005). At 12 years, patients with TAV-AS had a higher incidence of AS-CD than BAV-AS patients (p < 0.0001), resulting in significantly worse survival compared to BAV-AS (p < 0.0001). AS-CD were independently determined by multiple factors (MPG, age, sex, comorbidities, cardiac function; all p ≤ 0.039), and BAV was independently protective of most AS-CD (all p ≤ 0.05).ConclusionsIn this cohort, TAV-AS and BAV-AS progression rates were similar. Rapid progression did not affect survival and was determined by cardiac risk factors for BAV-AS (particularly in patients with BAV <60 years of age) and unmodifiable factors for TAV-AS. AS-CD and mortality were significantly higher in TAV-AS. Independent determinants of AS-CD were multifactorial, and BAV morphology was AS-CD protective. Therefore, the totality of AS burden (cardiac damage) is clinically crucial for TAV-AS, whereas attention to modifiable risk factors may be preventive for BAV-AS.     

Left Atrial Strain Impairment Precedes Geometric Remodeling as a Marker of Post-Myocardial Infarction Diastolic Dysfunction

ObjectivesThe aims of this study were to test the magnitude of agreement between echocardiography (echo)- and cardiac magnetic resonance (CMR)–derived left atrial (LA) strain and to study their relative diagnostic performance in discriminating diastolic dysfunction (DD) and predicting atrial fibrillation (AF).BackgroundsPeak atrial longitudinal strain (PALS) is a novel performance index. Utility of echo-quantified LA strain has yet to be prospectively tested in relation to current DD guidelines or compared to CMR.MethodsThe study population comprised 257 post-myocardial infarction (MI) patients undergoing echo and CMR, including prospective derivation (n = 157) and clinical validation (n = 100) cohorts. DD was graded on echo using established consensus guidelines blinded to strain results.ResultsPALS on both echo and CMR was nearly 2-fold lower among patients with versus no DD (p < 0.001) and was significantly different in those with mild versus no DD (p < 0.01). In contrast, LA geometric parameters including echo- and CMR-derived volumes were significantly different between advanced versus no DD groups (p < 0.001) but not between groups with mild versus no DD (all p > 0.05). Echo and CMR PALS yielded small differences irrespective of orientation and similar diagnostic performance for DD in the derivation (area under the curve [AUC]: 0.70 to 0.78) and validation (AUC: 0.75 to 0.78) cohorts. Impaired PALS on both modalities was independently associated with MI size (p < 0.001). During 4.4 ± 3.8 years of follow-up in the derivation cohort, 8% developed AF. Both 2-chamber echo- and CMR-derived PALS stratified arrhythmic risk (p = 0.004 and p = 0.02, respectively), including a 4-fold difference among patients in the lowest versus remainder of quartiles of echo-derived PALS (24% vs. 6%). Similarly, echo and CMR PALS were lower (both p < 0.05) among patients with subsequent heart failure hospitalizations.ConclusionsEcho-derived PALS parallels results of CMR, yields incremental diagnostic utility versus LA geometry for stratifying presence and severity of DD, and improves prediction of AF and congestive heart failure after MI.     

Diffuse Myocardial Fibrosis and Diastolic Function in Aortic Stenosis

ObjectivesThe aim of this study was to investigate the relationship between extracellular volume fraction (ECV), a noninvasive parameter that quantifies the degree of diffuse myocardial fibrosis on cardiac magnetic resonance (CMR), and left ventricular diastolic dysfunction (LVDD) in patients with aortic stenosis (AS).BackgroundMyocardial fibrosis on invasive myocardial biopsy is associated with LVDD. However, there is a paucity of data on the association between noninvasively quantified diffuse myocardial fibrosis and the degree of LVDD and how these are related to symptoms and long-term prognosis in patients with AS.MethodsPatients with moderate or severe AS (n = 191; mean age 68.4 years) and 30 control subjects without cardiovascular risk factors underwent CMR. LVDD grade was evaluated using echocardiography according to the 2016 American Society of Echocardiography/European Association of Cardiovascular Imaging guidelines. Clinical outcomes were defined as a composite of all-cause mortality or hospitalization for heart failure aggravation.ResultsPatients in higher ECV quintiles had a significantly higher prevalence of LVDD. Higher ECV was particularly associated with decreased myocardial relaxation (septal e′ <7 cm/s) and increased LV filling pressure (E/e′ ratio ≥15). Although both impaired diastolic function and higher ECV were significantly associated with a worse degree of dyspnea, patients with higher ECV showed greater dyspnea within the same grade of LVDD. During a median follow-up period of 5.6 years, 37 clinical events occurred. Increased ECV, as well as lower septal e′ and higher E/septal e′ ratio, were independent predictors of clinical events, irrespective of age, AS severity, aortic valve replacement, and left ventricular (LV) ejection fraction. ECV provided incremental prognostic value on top of clinical factors and LV systolic and diastolic function.ConclusionsDiffuse myocardial fibrosis, assessed using ECV on CMR, was associated with LVDD in patients with AS, but both ECV and LV diastolic function parameters provided a complementary explanation for dyspnea and clinical outcomes. Concomitant assessment of both LVDD and diffuse myocardial fibrosis may further identify patients with AS with greater symptoms and worse prognosis.     

Extracellular Volume in Primary Mitral Regurgitation

ObjectivesThis study used cardiovascular magnetic resonance (CMR) to evaluate whether elevated extracellular volume (ECV) was associated with mitral valve prolapse (MVP) or if elevated ECV was a consequence of remodeling independent of primary mitral regurgitation (MR) etiology.BackgroundReplacement fibrosis in primary MR is more prevalent in MVP; however, data on ECV as a surrogate for diffuse interstitial fibrosis in primary MR are limited.MethodsPatients with chronic primary MR underwent comprehensive CMR phenotyping and were stratified into an MVP cohort (>2 mm leaflet displacement on a 3-chamber cine CMR) and a non-MVP cohort. Factors associated with ECV and replacement fibrosis were assessed. The association of ECV and symptoms related to MR and clinical events (mitral surgery and cardiovascular death) was ascertained.ResultsA total of 424 patients with primary MR (229 with MVP and 195 non-MVP) were enrolled. Replacement fibrosis was more prevalent in the MVP cohort (34.1% vs. 6.7%; p < 0.001), with bi-leaflet MVP having the strongest association with replacement fibrosis (odds ratio: 10.5; p < 0.001). ECV increased with MR severity in a similar fashion for both MVP and non-MVP cohorts and was associated with MR severity but not MVP on multivariable analysis. Elevated ECV was independently associated with symptoms related to MR and clinical events.ConclusionsAlthough replacement fibrosis was more prevalent in MVP, diffuse interstitial fibrosis as inferred by ECV was associated with MR severity, regardless of primary MR etiology. ECV was independently associated with symptoms related to MR and clinical events. (DeBakey Cardiovascular Magnetic Resonance Study [DEBAKEY-CMR]; NCT04281823)     

Impact of Surgical and Transcatheter Aortic Valve Replacement in Low-Gradient Aortic Stenosis: A Meta-Analysis

ObjectivesThe aim of this study was to assess the impact of aortic valve replacement (AVR) on survival in patients with each subclass of low-gradient (LG) aortic stenosis (AS) and to compare outcomes following surgical AVR (SAVR) and transcatheter AVR (TAVR).BackgroundLG severe AS encompasses a wide variety of pathophysiology, including classical low-flow, LG (LF-LG), paradoxical LF-LG, and normal-flow, LG (NF-LG) AS, and uncertainty exists regarding the impact of AVR on each subclass of LG AS.MethodsPubMed and Embase were queried through October 2020 to identify studies comparing survival with different management strategies (SAVR, TAVR, and conservative) in patients with LG AS. Pairwise meta-analysis comparing AVR versus conservative management and network meta-analysis comparing SAVR versus TAVR versus conservative management were performed.ResultsThirty-two studies with a total of 6,515 patients and a median follow-up time of 24.2 months (interquartile range: 36.5 months) were included. AVR was associated with a significant decrease in all-cause mortality in classical LF-LG (hazard ratio [HR]: 0.42; 95% confidence interval [CI]: 0.36 to 0.48), paradoxical LF-LG (HR: 0.41; 95% CI: 0.29 to 0.57), and NF-LG (HR: 0.41; 95% CI: 0.27 to 0.62) AS compared with conservative management. SAVR and TAVR were each associated with a decrease in all-cause mortality in classical LF-LG (HR: 0.46 [95% CI: 0.38 to 0.55] and 0.49 [95% CI: 0.37 to 0.64], respectively), paradoxical LF-LG (HR: 0.42 [95% CI: 0.28 to 0.65] and 0.42 [95% CI: 0.25 to 0.72], respectively), and NF-LG (HR: 0.40 [95% CI: 0.21 to 0.77] and 0.46 [95% CI: 0.26 to 0.84], respectively) AS compared with conservative management. No significant difference was observed between SAVR and TAVR.ConclusionsIn all subclasses of LG AS, AVR was associated with a significant decrease in all-cause mortality regardless of surgical or transcatheter approach.     

Sex-Related Differences in the Extent of Myocardial Fibrosis in Patients With Aortic Valve Stenosis

ObjectivesThe aim of this study was to assess the effect of sex on myocardial fibrosis as assessed by using cardiac magnetic resonance (CMR) imaging in aortic stenosis (AS).BackgroundPrevious studies reported sex-related differences in the left ventricular (LV) remodeling response to pressure overload in AS. However, there are very few data regarding the effect of sex on myocardial fibrosis, a key marker of LV decompensation and adverse cardiac events in AS.MethodsA total of 249 patients (mean age 66 ± 13 years; 30% women) with at least mild AS were recruited from 2 prospective observational cohort studies and underwent comprehensive Doppler echocardiography and CMR examinations. On CMR, T1 mapping was used to quantify extracellular volume (ECV) fraction as a marker of diffuse fibrosis, and late gadolinium enhancement (LGE) was used to assess focal fibrosis.ResultsThere was no difference in age between women and men (age 66 ± 15 years vs 66 ± 12 years; p = 0.78). However, women presented with a better cardiovascular risk profile than men with less hypertension, dyslipidemia, diabetes, and coronary artery disease (all, p ≤ 0.10). As expected, LV mass index measured by CMR imaging was smaller in women than in men (p < 0.0001). Despite fewer comorbidities, women presented with larger ECV fraction (median: 29.0% [25th to 75th percentiles: 27.4% to 30.6%] vs. 26.8% [25th to 75th percentiles: 25.1% to 28.7%]; p < 0.0001) and similar LGE (median: 4.5% [25th–75th percentiles: 2.3% to 7.0%] vs. 2.8% [25th–75th percentiles: 0.6% to 6.8%]; p = 0.20) than men. In multivariable analysis, female sex remained an independent determinant of higher ECV fraction and LGE (all, p ≤ 0.05).ConclusionsWomen have greater diffuse and focal myocardial fibrosis independent of the degree of AS severity. These findings further emphasize the sex-related differences in LV remodeling response to pressure overload.     

Sex Differences in LV Remodeling and Hemodynamics in Aortic Stenosis: Sex-Specific Criteria for Severe Stenosis?

BackgroundThe current criteria for aortic stenosis (AS) severity have not incorporated sex-related differences.ObjectivesThe authors investigated sex-related serial changes in left ventricular (LV) structure/function and hemodynamics in AS.MethodsSerial echocardiograms of patients with severe AS (time 0; aortic valve area [AVA] ≤1 cm²) and ≥1 previous echocardiogram were compared between sexes.ResultsOf 927 patients (time 0: AVA 0.87 ± 0.11 cm², peak velocity 4.03 ± 0.65 m/s, mean Doppler systolic pressure gradient [MG] 40.6 ± 13.1 mm Hg), 393 (42%) were women. Women had smaller body surface area (BSA) (1.77 ± 0.22 m² vs 2.03 ± 0.20 m²; P < 0.001), lower stroke volume (SV) (81.1 ± 17.2 mL vs 88.3 ± 18.6 mL; P < 0.001), and more frequent low-gradient severe AS (n = 196 [50%] vs n = 181 [34%]; P < 0.001). Women consistently had smaller AVA, indexed AVA (AVAi), peak velocity, and MG than men. The difference in aortic valve gradient lessened when AVAi ≤0.6 cm²/m² was applied as severe AS (n = 694, women 43%, AVA 0.95 ± 0.17 cm², AVAi 0.50 ± 0.07 cm²/m²). Peak velocity (3.83 ± 0.66 m/s) and MG (36.5 ± 13.2 mm Hg) were lower based on AVAi severity criteria compared to those based on AVA. Men had a lower left ventricular ejection fraction (LVEF) (55.8% ± 14.8% vs 61.1% ± 11.7%; P < 0.001) and greater reduction in SV (?13.3 ± 19.6 mL vs ?7.4 ± 16.4 mL; P < 0.001) as AS progressed from moderate to severe. Concentric LV hypertrophy was more common and E/e? higher in women (21.2 ± 10.9 vs 18.8 ± 9.1; P < 0.001). SV, LVEF, AVA, peak velocity, and MG became precipitously worse when AVA reached 1.2 cm² in both sexes.ConclusionsSmaller BSA in women yields lower SV, resulting in lower aortic valve gradient than men. Indexed parameters by BSA are thus important in sex-related differences of aortic valve hemodynamics, but AVAi ≤0.6 cm²/m² includes individuals with moderate AS. Elevated filling pressure is more common in women. Men experience a larger reduction in SV and LVEF as AS progresses. The definition of AS severity may require different criteria between sexes.     

Left Ventricular Hypertrophy and Clinical Outcomes Over 5 Years After TAVR: An Analysis of the PARTNER Trials and Registries

ObjectivesThis study sought to evaluate the association between severity of left ventricular hypertrophy (LVH) before transcatheter aortic valve replacement (TAVR) and outcomes out to 5 years.BackgroundPrior studies assessing the association between baseline LVH and outcomes after surgical or TAVR for aortic stenosis (AS) have yielded conflicting results.MethodsPatients with severe symptomatic AS at intermediate or high risk in the PARTNER (Placement of Aortic Transcatheter Valve) 1, 2, and S3 trials and registries who received TAVR and had baseline measurements for left ventricular mass index (LVMi) were analyzed. The presence and severity of LVH was determined by LVMi using American Society of Echocardiography sex-specific cutoffs.ResultsAmong 4,280 patients, those with no (n = 1,325), mild (n = 777), moderate (n = 628), and severe (n = 1,550) LVH had 5-year rates of death of 32.8%, 37.3%, 37.2%, and 44.8%, respectively (p < 0.001), and 5-year rates of cardiovascular (CV) death or rehospitalization of 33.6%, 39.2%, 42.4%, and 49.2%, respectively (p < 0.001). After adjustment, severe LVH (compared with no LVH) was associated with increased all-cause death (adjusted hazard ratio: 1.16; 95% confidence interval: 1.00 to 1.34; p = 0.04) and CV death or rehospitalization (adjusted hazard ratio: 1.34; 95% confidence interval: 1.16 to 1.54; p < 0.001), but no increased hazard was observed for mild or moderate LVH. In spline analyses performed in males and females separately, there was a consistent linear association between increased LVMi and an increased adjusted hazard of CV mortality or rehospitalization. A similar relationship was observed for all-cause death in females, but not males.ConclusionsSevere baseline LVH is associated with higher 5-year death and rehospitalization rates after TAVR. These findings may have implications for the optimal timing of valve replacement and the potential role for medical therapy to slow or prevent LVH as AS progresses before valve replacement, but further studies are needed.     

Coronary Revascularization in Patients Undergoing Aortic Valve Replacement for Severe Aortic Stenosis

Aortic stenosis (AS) and coronary artery disease (CAD) frequently coexist, with up to two thirds of patients with AS having significant CAD. Given the challenges when both disease states are present, these patients require a tailored approach diagnostically and therapeutically. In this review the authors address the impact of AS and aortic valve replacement (AVR) on coronary hemodynamic status and discuss the assessment of CAD and the role of revascularization in patients with concomitant AS and CAD. Remodeling in AS increases the susceptibility of myocardial ischemia, which can be compounded by concomitant CAD. AVR can improve coronary hemodynamic status and reduce ischemia. Assessment of the significance of coexisting CAD can be done using noninvasive and invasive metrics. Revascularization in patients undergoing AVR can benefit certain patients in whom CAD is either prognostically or symptomatically important. Identifying this cohort of patients is challenging and as yet incomplete. Patients with dual pathology present a diagnostic and therapeutic challenge; both AS and CAD affect coronary hemodynamic status, they provoke similar symptoms, and their respective treatments can have an impact on both diseases. Decisions regarding coronary revascularization should be based on understanding this complex relationship, using appropriate coronary assessment and consensus within a multidisciplinary team.     

Prevalence and Outcomes of Concomitant Aortic Stenosis and Cardiac Amyloidosis

BackgroundOlder patients with severe aortic stenosis (AS) are increasingly identified as having cardiac amyloidosis (CA). It is unknown whether concomitant AS-CA has worse outcomes or results in futility of transcatheter aortic valve replacement (TAVR).ObjectivesThis study identified clinical characteristics and outcomes of AS-CA compared with lone AS.MethodsPatients who were referred for TAVR at 3 international sites underwent blinded research core laboratory ^99mtechnetium-3,3-diphosphono-1,2-propanodicarboxylic acid (DPD) bone scintigraphy (Perugini grade 0: negative; grades 1 to 3: increasingly positive) before intervention. Transthyretin-CA (ATTR) was diagnosed by DPD and absence of a clonal immunoglobulin, and light-chain CA (AL) was diagnosed via tissue biopsy. National registries captured all-cause mortality.ResultsA total of 407 patients (age 83.4 ± 6.5 years; 49.8% men) were recruited. DPD was positive in 48 patients (11.8%; grade 1: 3.9% [n = 16]; grade 2/3: 7.9% [n = 32]). AL was diagnosed in 1 patient with grade 1. Patients with grade 2/3 had worse functional capacity, biomarkers (N-terminal pro-brain natriuretic peptide and/or high-sensitivity troponin T), and biventricular remodeling. A clinical score (RAISE) that used left ventricular remodeling (hypertrophy/diastolic dysfunction), age, injury (high-sensitivity troponin T), systemic involvement, and electrical abnormalities (right bundle branch block/low voltages) was developed to predict the presence of AS-CA (area under the curve: 0.86; 95% confidence interval: 0.78 to 0.94; p < 0.001). Decisions by the heart team (DPD-blinded) resulted in TAVR (333 [81.6%]), surgical AVR (10 [2.5%]), or medical management (65 [15.9%]). After a median of 1.7 years, 23% of patients died. One-year mortality was worse in all patients with AS-CA (grade: 1 to 3) than those with lone AS (24.5% vs. 13.9%; p = 0.05). TAVR improved survival versus medical management; AS-CA survival post-TAVR did not differ from lone AS (p = 0.36).ConclusionsConcomitant pathology of AS-CA is common in older patients with AS and can be predicted clinically. AS-CA has worse clinical presentation and a trend toward worse prognosis, unless treated. Therefore, TAVR should not be withheld in AS-CA.     

A Novel Assessment Using Projected Transmitral Gradient Improves Diagnostic Yield of Doppler Hemodynamics in Rheumatic and Calcific Mitral Stenosis

ObjectivesThe aims of this study were to: 1) develop a formula for projected transmitral gradient (TMG), expected gradient under normal heart rate (HR), and stroke volume (SV); and 2) assess the prognostic value of projected TMG.BackgroundIn mitral stenosis (MS), TMG is highly dependent on hemodynamics, often leading to discordance between TMG and mitral valve area.MethodsAll patients with suspected MS based on echocardiography from 2001 to 2017 were analyzed. Data were randomly split (2:1); projected TMG was modeled in the derivation cohort, then tested in the validation cohort. The composite endpoint was death or mitral valve intervention.ResultsOf 4,973 patients with suspected MS, severe and moderate MS, defined as mitral valve area ≤1.5 and >1.5 to 2.0 cm², were present in 437 (9%) and 936 (19%), respectively. In the derivation cohort (n = 3,315; age 73 ± 12 years; 34% male), corresponding gradients were TMG ≥6 and 4 to <6 mm Hg, respectively, under normal hemodynamics. Based on the impact of hemodynamics on TMG, the formula was projected TMG = TMG ? 0.07 (HR ? 70) ? 0.03 (SV ? 97) in men and projected TMG = TMG ? 0.08 (HR ? 72) ? 0.04 (SV ? 84) in women. In the validation cohort (n = 1,658), projected TMG had better agreement with MS severity than TMG (kappa 0.61 vs. 0.28). Among 281 patients with TMG ≥6 mm Hg, projected TMG ≥6 mm Hg, present in 171 patients (61%), was associated with higher probability of the endpoint versus projected TMG <6 mm Hg (adjusted hazard ratio: 1.8; 95% confidence interval: 1.2 to 2.6; p < 0.01).ConclusionsThe novel concept of projected TMG, constructed using the observed impact of HR and SV on TMG, significantly improved the concordance of gradient and valve area in MS and provided better risk stratification than TMG.     

Regional Replacement and Diffuse Interstitial Fibrosis in Aortic Regurgitation: Prognostic Implications From Cardiac Magnetic Resonance

ObjectivesThis study used cardiac magnetic resonance (CMR) to assess left ventricular (LV) remodeling in chronic aortic regurgitation (AR) to identify both forms of myocardial fibrosis and examine its association with clinical outcomes.BackgroundChronic AR leads to LV remodeling, which is associated with 2 forms of myocardial fibrosis: regional replacement fibrosis that is directly imaged by late gadolinium enhancement (LGE) CMR; and diffuse interstitial fibrosis, which can be inferred by T1 mapping techniques.MethodsPatients with chronic AR who were undergoing contrast CMR with T1 mapping for valve assessment from 2011 to 2018 were enrolled. Patients with a confounding etiology of myocardial fibrosis were excluded. In addition to quantification of AR severity and LV volumetrics, LGE and T1 mapping pre- and post-contrast were performed to measure extracellular volume (ECV) and indexed ECV (iECV). Patients were followed up longitudinally to assess for the composite event of death and the need for aortic valve replacement.ResultsA total of 177 patients with isolated chronic AR were included (66% males, median age 58 years [IQR: 47.0-68.0 years]) with a median follow up of 2.5 years (IQR: 1.07-3.56 years). The iECV significantly increased with AR severity (P < 0.001), whereas ECV and replacement fibrosis did not (P = NS). On multivariate analysis, iECV remained associated with the composite event (P = 0.01). On Kaplan-Meier analysis stratified by AR regurgitant fraction (RF) and iECV, patients with AR RF severity ≥30% and iECV ≥24 mL/m² demonstrated the highest event rate.ConclusionsAmong CMR biomarkers of fibrosis, iECV was more closely associated than replacement fibrosis or ECV with survival free of aortic valve replacement.     

Unsupervised clustering of patients with severe aortic stenosis: A myocardial continuum

BackgroundTraditional statistics, based on prediction models with a limited number of prespecified variables, are probably not adequate to provide an appropriate classification of a condition that is as heterogeneous as aortic stenosis (AS).AimsTo investigate a new classification system for severe AS using phenomapping.MethodsConsecutive patients from a referral centre (training cohort) who met the echocardiographic definition of an aortic valve area (AVA) ≤ 1 cm² were included. Clinical, laboratory and imaging continuous variables were entered into an agglomerative hierarchical clustering model to separate patients into phenogroups. Individuals from an external validation cohort were then assigned to these original clusters using the K nearest neighbour (KNN) function and their 5-year survival was compared after adjustment for aortic valve replacement (AVR) as a time-dependent covariable.ResultsIn total, 613 patients were initially recruited, with a mean ± standard deviation AVA of 0.72 ± 0.17 cm². Twenty-six variables were entered into the model to generate a specific heatmap. Penalized model-based clustering identified four phenogroups (A, B, C and D), of which phenogroups B and D tended to include smaller, older women and larger, older men, respectively. The application of supervised algorithms to the validation cohort (n = 1303) yielded the same clusters, showing incremental cardiac remodelling from phenogroup A to phenogroup D. According to this myocardial continuum, there was a stepwise increase in overall mortality (adjusted hazard ratio for phenogroup D vs A 2.18, 95% confidence interval 1.46–3.26; P < 0.001).ConclusionsArtificial intelligence re-emphasizes the significance of cardiac remodelling in the prognosis of patients with severe AS and highlights AS not only as an isolated valvular condition, but also a global disease.     

Transcatheter ViV Versus Redo Surgical AVR for the Management of Failed Biological Prosthesis: Early and Late Outcomes in a Propensity-Matched Cohort

ObjectivesThe aim of this study was to compare early and late outcomes between redo surgical aortic valve replacement (AVR) and valve-in-valve (ViV) transcatheter AVR.BackgroundPublished studies to date comparing redo surgical AVR (RS) with ViV transcatheter AVR for failed biological prostheses have been small and limited to early outcomes.MethodsClinical and administrative databases for Ontario, Canada’s most populous province, were linked to obtain patients undergoing ViV and RS for failed previous biological prostheses. Propensity score matching was performed to account for differences in baseline characteristics. Early outcomes were compared using the McNemar test. Late mortality was compared between the matched groups using a Cox proportional hazards model.ResultsA total of 558 patients undergoing intervention for failed biological prostheses between March 31, 2008, and September 30, 2017, at 11 Ontario institutions (ViV, n = 214; RS, n = 344) were included. Patients who underwent ViV were older and had more comorbidities. Propensity matching on 27 variables yielded similar groups for comparison (n = 131 pairs). Mean time from initial AVR to RS or ViV was 8.6 ± 4.4 years and 11.3 ± 4.5 years, respectively. Thirty-day mortality was significantly lower with ViV compared with RS (absolute risk difference: −7.5%; 95% confidence interval: −12.6% to −2.3%). The rates of permanent pacemaker implantation and blood transfusions were also lower with ViV, as was length of stay. Survival at 5 years was higher with ViV (76.8% vs. 66.8%; hazard ratio: 0.55; 95% confidence interval: 0.30 to 0.99; p = 0.04).ConclusionsViV TAVR was associated with lower early mortality, morbidity, and length of hospital stay and with increased survival compared with RS and may be the preferred approach for the treatment of failed biological prostheses.     

Aortic Stenosis Progression: A Systematic Review and Meta-Analysis

BackgroundAortic valve stenosis is a progressive disorder with variable progression rates. The factors affecting aortic stenosis (AS) progression remain largely unknown.ObjectivesThis systematic review and meta-analysis sought to determine AS progression rates and to assess the impact of baseline AS severity and sex on disease progression.MethodsThe authors searched Medline, Embase, and the Cochrane Central Register of Controlled Trials from inception to July 1, 2020, for prospective studies evaluating the progression of AS with the use of echocardiography (mean gradient [MG], peak velocity [PV], peak gradient [PG], or aortic valve area [AVA]) or computed tomography (calcium score [AVC]). Random-effects meta-analysis was performed to evaluate the rate of AS progression for each parameter stratified by baseline severity, and meta-regression was performed to determine the impact of baseline severity and of sex on AS progression rate.ResultsA total of 24 studies including 5,450 patients (40% female) met inclusion criteria. The pooled annualized progression of MG was +4.10 mm Hg (95% CI: 2.80-5.41 mm Hg), AVA −0.08 cm² (95% CI: 0.06-0.10 cm²), PV +0.19 m/s (95% CI: 0.13-0.24 m/s), PG +7.86 mm Hg (95% CI: 4.98-10.75 mm Hg), and AVC +158.5 AU (95% CI: 55.0-261.9 AU). Increasing baseline severity of AS was predictive of higher rates of progression for MG (P < 0.001), PV (P = 0.001), and AVC (P < 0.001), but not AVA (P = 0.34) or PG (P = 0.21). Only 4 studies reported AS progression stratified by sex, with only PV and AVC having 3 studies to perform a meta-analysis. No difference between sex was observed for PV (P = 0.397) or AVC (P = 0.572), but the level of confidence was low.ConclusionsThis study provides progression rates for both hemodynamic and anatomic parameters of AS and shows that increasing hemodynamic and anatomic baseline severity is associated with faster AS progression. More studies are needed to determine if sex differences affect AS progression. (Aortic Valve Stenosis Progression Rate: A Systematic Review and Meta-Analysis; CRD42021207726)     

Peak Troponin and CMR to Guide Management in Suspected ACS and Nonobstructive Coronary Arteries

BackgroundPatients presenting with acute coronary syndrome (ACS) and nonobstructive coronary arteries are a diagnostic dilemma. Cardiac magnetic resonance (CMR) has an overall diagnostic yield of ～75%; however, in ～25% of patients, CMR does not identify any myocardial injury. Identifying the underlying diagnosis has important clinical implications for patients’ management and outcome.ObjectivesThe authors sought to assess whether the combination of CMR and peak troponin levels in patients with ACS and nonobstructive coronary arteries would lead to increased diagnostic yield.MethodsConsecutive patients with ACS and nonobstructive coronary arteries without an obvious cause underwent CMR. The primary endpoint of the study was the diagnostic yield of CMR. The Youden index was used to find the optimal diagnostic cut point for peak troponin T to combine with CMR to improve diagnostic yield. Logistic or Cox regression models were used to estimate predictors of a diagnosis by CMR.ResultsA total of 719 patients met the inclusion criteria. The peak troponin T threshold for optimal diagnostic sensitivity and specificity was 211 ng/L. Overall, CMR has a diagnostic yield of 74%. CMR performed <14 days from presentation and with a peak troponin of ≥211 ng/L (n = 198) leads to an improved diagnostic yield (94% vs 72%) compared with CMR performed ≥14 days (n = 245). When CMR was performed <14 days and with a peak troponin of <211 ng/L, the diagnostic yield was 76% (n = 86) compared with 53% (n = 190) when performed ≥14 days. An increase in 1 peak troponin decile increases the odds of the CMR identifying a diagnosis by 20% (OR: 1.20; P = 0.008, 95% CI: 1.05-1.36).ConclusionsThe combination of CMR performed <14 days from presentation and peak troponin T ≥211 ng/L leads to a very high diagnostic yield (94%) on CMR. The diagnostic yield remains high (72%) even when CMR is performed ≥14 days from presentation, but reduces to 53% when peak troponin T was <211 ng/L.