Effect of Regional Upper Septal Hypertrophy on Echocardiographic Assessment of Left Ventricular Mass and Remodeling in Aortic Stenosis.

BACKGROUND: Transthoracic echocardiography (TTE) is the reference method for evaluation of aortic stenosis (AS), and it is extensively used to quantitate left ventricular (LV) mass and volumes. Regional upper septal hypertrophy (USH) or septal bulge is a frequent finding in patients with AS and may lead to overestimation of LV mass when using linear measurements. The objective of this study was to compare estimates of LV mass obtained by two-dimensional transthoracic echocardiographic LV dimensions measured at different levels of the LV cavity with those obtained by cardiovascular magnetic resonance (CMR). METHODS: One hundred six patients (mean age, 63 ± 15 years; 68% men) with AS were included in this subanalysis of the PROGRESSA study. Two-dimensional transthoracic echocardiographic measurements of LV dimensions were obtained at the basal level (BL; as recommended in guidelines), immediately below the septal bulge (BSB), and at a midventricular level (ML). Regional USH was defined as a basal interventricular septal thickness ≥ 13 mm and >1.3 times the thickness of the septal wall at the ML. Agreement between transthoracic echocardiographic and CMR measures was evaluated using Bland-Altman analysis. RESULTS: The distribution of AS severity was mild in 23%, moderate in 57%, and severe in 20% of patients. Regional USH was present in 28 patients (26%). In the whole cohort, two-dimensional TTE overestimated LV mass (bias: BL, +60 ± 31 g; BSB, +59 ± 32 g; ML, +54 ± 32 g; P = .02). The biplane Simpson method slightly but significantly underestimated LV end-diastolic volume (bias -10 ± 20 mL, P < .001) compared with CMR. Overestimation of LV mass was more marked in patients with USH when measuring at the BL and was significantly lower when measuring LV dimensions at the ML (P < .025 vs BL and BSB). CONCLUSIONS: Two-dimensional TTE systematically overestimated LV mass and underestimated LV volumes compared with CMR. However, the bias between TTE and CMR was less important when measuring at the ML. Measurements at the BL as suggested in guidelines should be avoided, and measurements at the ML should be preferred in patients with AS, especially in those with USH.

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

OBJECTIVES: The 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). BACKGROUND: Previous 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. METHODS: A 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. RESULTS: There 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). CONCLUSIONS: Women 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.

Cardiac magnetic resonance versus transthoracic echocardiography for the assessment and quantification of aortic regurgitation in patients undergoing transcatheter aortic valve implantation.

BACKGROUND: The transthoracic echocardiographic (TTE) evaluation of the severity of residual aortic regurgitation (AR) following transcatheter aortic valve implantation (TAVI) has been controversial and lacks validation. OBJECTIVES: This study sought to compare TTE and cardiac magnetic resonance (CMR) for assessment of AR in patients undergoing TAVI with a balloon-expandable valve. METHODS: TTE and CMR exams were performed pre-TAVI in 50 patients and were repeated postprocedure in 42 patients. All imaging data were analysed in centralised core laboratories. RESULTS: The severity of native AR as determined by multiparametric TTE approach correlated well with the regurgitant volume and regurgitant fraction determined by CMR prior to TAVI (Rs=0.79 and 0.80, respectively; p<0.001 for both). However, after TAVI, the correlation between the prosthetic AR severity assessed by TTE and regurgitant volume and fraction measured by CMR was only modest (Rs=0.59 and 0.59, respectively; p<0.001 for both), with an underestimation of AR severity by TTE in 61.9% of patients (1 grade in 59.5%). The TTE jet diameter in parasternal view and the multiparametric approach (Rs=0.62 and 0.59, respectively; both with p<0.001) showed the best correlation with CMR regurgitant fraction post-TAVI. The circumferential extent of prosthetic paravalvular regurgitation showed a poor correlation with CMR regurgitant volume and fraction (Rs=0.32, p=0.084; Rs=0.36, p=0.054, respectively). CONCLUSIONS: The severity of AR following TAVI with a balloon-expandable valve was underestimated by echocardiography as compared with CMR. The jet diameter, but not the circumferential extent of the leaks, and the multiparametric echocardiography integrative approach best correlated with CMR findings. These results provide important insight into the evaluation of AR severity post-TAVI.

Risk score, causes, and clinical impact of failure of transradial approach for percutaneous coronary interventions.

OBJECTIVES: To study the causes of and to develop a risk score for failure of transradial approach (TRA) for percutaneous coronary intervention (PCI). BACKGROUND: TRA-PCI failure has been reported in 5% to 10% of cases. METHODS: TRA-PCI failure was categorized as primary (clinical reasons) or crossover failure. Multivariate analysis was performed to determine independent predictors of TRA-PCI failure, and an integer risk score was developed. RESULTS: From January to June 2010, TRA-PCI was attempted in 1,609 (97.3%) consecutive patients, whereas 45 (2.7%) had primary TRA-PCI failure. Crossover TRA-PCI failure occurred in 30 (1.8%) patients. Causes of primary TRA-PCI failure included chronic radial artery occlusion (11%), previous coronary artery bypass graft (27%), and cardiogenic shock (20%). Causes for crossover TRA-PCI failure included: inadequate puncture in 17 patients (57%); radial artery spasm in 5 (17%); radial loop in 4 (13%); subclavian tortuosity in 2 (7%); and inadequate guide catheter support in 2 (7%) patients. Female sex (odds ratio [OR]: 3.2; 95% confidence interval [CI]: 1.95 to 5.26, p < 0.0001), previous coronary artery bypass graft (OR: 6.1; 95% CI: 3.63 to 10.05, p < 0.0001), and cardiogenic shock (OR: 11.2; 95% CI: 2.78 to 41.2, p = 0.0011) were independent predictors of TRA-PCI failure. Risk score values from 0 to 7 predicted a TRA-PCI failure rate from 2% to 80%. CONCLUSIONS: In a high-volume radial center, 2.7% of patients undergoing PCI are excluded from initial TRA on clinical grounds, whereas crossover to femoral approach is required in only 1.8% of the cases. A new simple clinical risk score is developed to predict TRA-PCI failure.

Routine versus selective cardiac magnetic resonance in non-ischemic heart failure - OUTSMART-HF: study protocol for a randomized controlled trial (IMAGE-HF (heart failure) project 1-B).

BACKGROUND: Imaging has become a routine part of heart failure (HF) investigation. Echocardiography is a first-line test in HF given its availability and it provides valuable diagnostic and prognostic information. Cardiac magnetic resonance (CMR) is an emerging clinical tool in the management of patients with non-ischemic heart failure. Current ACC/AHA/CCS/ESC guidelines advocate its role in the detection of a variety of cardiomyopathies but there is a paucity of high quality evidence to support these recommendations.The primary objective of this study is to compare the diagnostic yield of routine cardiac magnetic resonance versus standard care (that is, echocardiography with only selective use of CMR) in patients with non-ischemic heart failure. The primary hypothesisis that the routine use of CMR will lead to a more specific diagnostic characterization of the underlying etiology of non-ischemic heart failure. This will lead to a reduction in the non-specific diagnoses of idiopathic dilated cardiomyopathy and HF with preserved ejection fraction. DESIGN: Tertiary care sites in Canada and Finland, with dedicated HF and CMR programs, will randomize consecutive patients with new or deteriorating HF to routine CMR or selective CMR. All patients will undergo a standard clinical echocardiogram and the interpreter will assign the most likely HF etiology. Those undergoing CMR will also have a standard examination and will be assigned a HF etiology based upon the findings. The treating physician's impression about non-ischemic HF etiology will be collected following all baseline testing (including echo ± CMR). Patients will be followed annually for 4 years to ascertain clinical outcomes, quality of life and cost. The expected outcome is that the routine CMR arm will have a significantly higher rate of infiltrative, inflammatory, hypertrophic, ischemic and 'other' cardiomyopathy than the selective CMR group. DISCUSSION: This study will be the first multicenter randomized, controlled trial evaluating the role of CMR in non-ischemic HF. Non-ischemic HF patients will be randomized to routine CMR in order to determine whether there are any gains over management strategies employing selective CMR utilization. The insight gained from this study should improve appropriate CMR use in HF. TRIAL REGISTRATION: NCT01281384.

Incidence and clinical impact of concurrent chronic total occlusion according to gender in ST-elevation myocardial infarction.

OBJECTIVES: To determine the prevalence of a concurrent CTO in men and women and to examine its impact on mortality. BACKGROUND: The impact of chronic total occlusion (CTO) in patients with ST-elevation myocardial infarction (STEMI) according to gender has not been assessed. METHODS: Patients referred with STEMI were categorized into single vessel disease (SVD), multivessel disease (MVD) without, with 1 or > 1 CTO. The primary end-point was the 1-year mortality. RESULTS: Among the 2020 STEMI patients included between 2006 and 2011, 24% were female. Women were older, had more hypertension and renal failure (P < 0.0001 for all). The prevalence of 1 or > 1 concurrent CTO was similar in both sexes, 7 and 1%, respectively. Early and late mortality was significantly higher in women compared with men (P < 0.0001). In women, the mortality was significantly worse in patients with > 1 CTO (100%) and with 1 CTO (36.4%) compared with those with MVD without CTO (18.4%) or with SVD (10.4%) (P < 0.0001). MVD with and without concurrent CTO were both independent predictors of 1-year mortality in women (HR 3.58; 95 % CI 1.69-7.18 and HR 2.76; 95 % CI 1.33-5.51) whereas only MVD with CTO was predictive in men (HR 2.19; 95% CI 1.20-3.97). CONCLUSIONS: Among unselected STEMI patients, the prevalence of CTO was equal in both sexes whereas early and late mortality remained significantly higher in women. Other factors than the presence of a concurrent CTO must be explored to explain differences in survival after STEMI between women and men.

Clinical outcomes after multilesion percutaneous coronary intervention: comparison between exclusive and selective use of drug-eluting stents.

OBJECTIVES: This study compared acute and late outcomes following a strategy of selective drug-eluting stent (DES) use guided by a set of 4 criteria defining higher risk of in-stent restenosis compared to an exclusive DES strategy in 362 patients with multilesion (n = 900) percutaneous coronary interventions. RESULTS: At a mean follow up of 412 +/- 110 days, major adverse cardiac events (death, myocardial infarction, revascularization) were 16.8% in the exclusive DES group compared to 18.4% in the selective DES group (p = 0.78). By univariate analysis, revascularization rates (9.9% in the exclusive DES group versus 10.5% in the selective DES group; p = 1.0) and target lesion revascularization (TLR) rates (5.5% versus 6.2%; p = 0.77) were similar in the 2 groups. By multivariate analysis adjusted by propensity score to account for differences in baseline characteristics, the strategy of exclusive DES use was not associated with lower risks of revascularization (hazard ratio [HR]: 0.91, 95% confidence interval [CI] 0.64-1.29) or TLR (HR: 0.81, 95% CI 0.59-1.08) compared with selective DES use. Using the Academic Research Consortium criteria, stent thrombosis occurred in 6/161 (3.7%) cases in the exclusive DES group and in 1/201 (0.5%) case in the selective DES group (p = 0.03). CONCLUSIONS: In patients with multiple coronary lesions, a selective DES strategy for lesions at higher risk of restenosis and bare-metal stents for other lesions was safe and effective when compared to the exclusive use of DES. A large, prospective, randomized trial is required to validate a criteria-based selective DES strategy compared to systematic DES use.

Treatment delays in patients undergoing primary percutaneous coronary intervention for ST elevation myocardial infarction at the Quebec Heart and Lung Institute.

BACKGROUND: Current guidelines for ST elevation myocardial infarction (STEMI) recommend performing primary percutaneous coronary intervention (PCI) within 90 min of hospital arrival. However, recent data suggest that in a real-world setting, median door-to-balloon (DTB) time is closer to 180 min for transfer patients, with less than 5% of patients being treated within 90 min. A retrospective observational study was conducted to assess time to treatment in patients undergoing primary PCI at the Quebec Heart and Lung Institute (QHLI). METHODS: Consecutive lytic-eligible patients undergoing primary PCI at the QHLI for STEMI between April 2004 and March 2005 were included in the present analysis. The primary evaluation was DTB time measured from arrival at the first hospital to first balloon inflation. Clinical outcomes were in-hospital death, reinfarction and bleeding. DTB times and hospital outcomes of patients transferred from referring hospitals were compared with those of patients presenting directly to the QHLI. RESULTS: During the study period, 203 lytic-eligible patients were treated with primary PCI. Sixty-nine patients presented directly to the QHLI and 134 were transferred from other hospitals. Six transfer patients were excluded because of missing time variables. The median DTB time was 114 min in transfer patients, compared with 87 min in patients presenting directly to the QHLI (P<0.001). DTB time was less than 90 min in 24% of the transfer population compared with 55% of patients presenting directly to the QHLI (P<0.001). In patients referred from hospitals within a radius of 30 km from the QHLI (n=100), median DTB time was 106 min with 30% receiving PCI within 90 min. In these patients, estimated PCI-related delay was 74 min. For patients presenting to hospitals beyond 30 km (n=28), median DTB time was 142 min with 4% receiving reperfusion within 90 min. In these patients, estimated PCI-related delay was 110 min. Median DTB time for patients presenting during off hours at the QHLI was 92 min compared with 79 min for patients presenting during regular business hours (P=0.02). In patients transferred from other hospitals, median DTB time was 118 min during off hours and 108 min during normal business hours (P=0.07). CONCLUSIONS: A DTB time of less than 90 min can be achieved in the majority of patients presenting directly to a primary PCI centre. However, for patients presenting to community hospitals, transfer for primary PCI is often associated with delayed revascularization. The present study highlights the need for careful patient selection when deciding between on-site thrombolytic therapy and transfer for primary PCI for STEMI patients presenting to hospitals without PCI facilities.