Left ventricular remodeling and hypertrophy in patients with aortic stenosis: insights from cardiovascular magnetic resonance.

BACKGROUND: Cardiovascular magnetic resonance (CMR) is the gold standard non-invasive method for determining left ventricular (LV) mass and volume but has not been used previously to characterise the LV remodeling response in aortic stenosis. We sought to investigate the degree and patterns of hypertrophy in aortic stenosis using CMR. METHODS: Patients with moderate or severe aortic stenosis, normal coronary arteries and no other significant valve lesions or cardiomyopathy were scanned by CMR with valve severity assessed by planimetry and velocity mapping. The extent and patterns of hypertrophy were investigated using measurements of the LV mass index, indexed LV volumes and the LV mass/volume ratio. Asymmetric forms of remodeling and hypertrophy were defined by a regional wall thickening ≥ 13 mm and >1.5-fold the thickness of the opposing myocardial segment. RESULTS: Ninety-one patients (61 ± 21 years; 57 male) with aortic stenosis (aortic valve area 0.93 ± 0.32 cm2) were recruited. The severity of aortic stenosis was unrelated to the degree (r2=0.012, P=0.43) and pattern (P=0.22) of hypertrophy. By univariate analysis, only male sex demonstrated an association with LV mass index (P=0.02). Six patterns of LV adaption were observed: normal ventricular geometry (n=11), concentric remodeling (n=11), asymmetric remodeling (n=11), concentric hypertrophy (n=34), asymmetric hypertrophy (n=14) and LV decompensation (n=10). Asymmetric patterns displayed considerable overlap in appearances (wall thickness 17 ± 2mm) with hypertrophic cardiomyopathy. CONCLUSIONS: We have demonstrated that in patients with moderate and severe aortic stenosis, the pattern of LV adaption and degree of hypertrophy do not closely correlate with the severity of valve narrowing and that asymmetric patterns of wall thickening are common.

Giant aneurysm of bilateral coronary arteries with multimodality imaging representations.

Giant coronary artery aneurysms are rare, with reported incidence of 0.02-0.2% (Morita H, Ozawa H, Yamazaki S, Yamauchi Y, Tsuji M, Katsumata T, et al. A case of giant coronary artery aneurysm with fistulous connection to the pulmonary artery: a case report and review of the literature. Intern Med. 2012; 51:1361-6.). Multiple giant aneurysms involving all three coronary arteries are even rarer. We report a rare case of multiple giant aneurysms involving the right coronary, left anterior descending and left circumflex arteries, supplemented with excellent multimodality imaging representations, i.e. plain radiograph, echocardiography, magnetic resonance imaging and computed tomography coronary angiogram.

Late gadolinium enhancement as a potential marker of increased perioperative risk in aortic valve replacement.

OBJECTIVES Risk assessment of patients with aortic stenosis (AS) undergoing aortic valve replacement (AVR) is challenging. We set out to determine the impact of myocardial late gadolinium enhancement (LGE), as detected by cardiovascular magnetic resonance (CMR), on postoperative outcomes following AVR. METHODS A prospective observational study was conducted on patients undergoing CMR using the LGE technique within 1 year of subsequent AVR. Patients were categorized into absent, mid-wall or infarct patterns of LGE by independent observers blinded to all clinical data, and data were collected with regard to 30-day mortality, major adverse cardiac and cerebrovascular events (MACCE) and postoperative complications. RESULTS A total of 63 patients were studied. Twenty-five patients had no LGE; 20 had mid-wall LGE and 18 had an infarct pattern. The incidence of MACCE, cerebrovascular accident (CVA) and heart block were significantly higher in the mid-wall group compared with the other two groups (MACCE: 25 vs. 0 vs. 5%, P = 0.014; CVA: 20 vs. 0 vs. 0%, P = 0.013; heart block: 30 vs. 4 vs. 12%, P = 0.050). Patients with no LGE had no 30-day MACCE events and no deaths up to 2 years of follow-up. CONCLUSIONS The myocardial LGE holds promise as a means of predicting risk prior to AVR for AS.

An unusual cause of acute limb ischemia: aortic intimal sarcoma.

Acute limb ischemia, a serious medical condition characterized by a rapid decrease in limb perfusion, often threatens limb viability. Acute limb ischemia can be secondary to multitude of causes, with the two most common being embolus and thrombosis in situ secondary to underlying peripheral artery disease. In this report we present an unusual case of acute limb ischemia secondary to intimal sarcoma of the thoracic aorta and outline the role of cardiovascular magnetic resonance imaging in such cases.

Midwall fibrosis is an independent predictor of mortality in patients with aortic stenosis.

OBJECTIVES: The goal of this study was to assess the prognostic significance of midwall and infarct patterns of late gadolinium enhancement (LGE) in aortic stenosis. BACKGROUND: Myocardial fibrosis occurs in aortic stenosis as part of the hypertrophic response. It can be detected by LGE, which is associated with an adverse prognosis in a range of other cardiac conditions. METHODS: Between January 2003 and October 2008, consecutive patients with moderate or severe aortic stenosis undergoing cardiovascular magnetic resonance with administration of gadolinium contrast were enrolled into a registry. Patients were categorized into absent, midwall, or infarct patterns of LGE by blinded independent observers. Patient follow-up was completed using patient questionnaires, source record data, and the National Strategic Tracing Service. RESULTS: A total of 143 patients (age 68 ± 14 years; 97 male) were followed up for 2.0 ± 1.4 years. Seventy-two underwent aortic valve replacement, and 27 died (24 cardiac, 3 sudden cardiac deaths). Compared with those with no LGE (n = 49), univariate analysis revealed that patients with midwall fibrosis (n = 54) had an 8-fold increase in all-cause mortality despite similar aortic stenosis severity and coronary artery disease burden. Patients with an infarct pattern (n = 40) had a 6-fold increase. Midwall fibrosis (hazard ratio: 5.35; 95% confidence interval: 1.16 to 24.56; p = 0.03) and ejection fraction (hazard ratio: 0.96; 95% confidence interval: 0.94 to 0.99; p = 0.01) were independent predictors of all-cause mortality by multivariate analysis. CONCLUSIONS: Midwall fibrosis was an independent predictor of mortality in patients with moderate and severe aortic stenosis. It has incremental prognostic value to ejection fraction and may provide a useful method of risk stratification.

Case report: Completely unroofed coronary sinus with a left superior vena cava draining into the left atrium studied by cardiovascular magnetic resonance.

A persistent left superior vena cava (LSVC) draining through a dilated coronary sinus into the right atrium is a relatively common congenital cardiovascular anomaly. It is readily identified by cardiovascular magnetic resonance (CMR). However, a LSVC draining into the left atrium (LA) and associated with unroofing of the coronary sinus, with resulting interatrial communication, is rare and may have important clinical consequences. As with any large atrial septal defect, it can be associated with a higher than expected incidence of pulmonary arterial hypertension, systemic embolization, and brain abscesses. In this report, we present a case of a completely unroofed coronary sinus with a persistent LSVC draining directly into the LA and illustrate the role of CMR in the diagnosis and evaluation of such anomalies.