Safety and feasibility of dobutamine stress echocardiography in symptomatic high gradient aortic stenosis patients scheduled for transcatheter aortic valve implantation.

PURPOSE: We aimed to study the safety and feasibility of low-dose dobutamine stress echocardiography in a symptomatic high gradient aortic stenosis population scheduled for transfemoral transcatheter aortic valve implantation (TAVI) and to quantify left ventricular (LV) flow reserve. METHODS: Fifty patients underwent dobutamine stress echocardiography with 5 minutes increments of 5 µg/kg/min up to 20 µg/kg/min until the heart rate increased ≥20 beats/min from baseline or exceeded 100 beats/min. Other criteria for discontinuing the infusion were major adverse events: ventricular arrhythmia, persistent supraventricular arrhythmia, pulmonary edema, chest pain with significant ST-changes, or minor events: ST-changes, drop in systolic blood pressure >30 mmHg, mild chest pain, and/or dyspnea. LV flow reserve was defined as an increase in stroke volume ≥20% during the test. RESULTS: Of 50 patients, 45 completed the test according to protocol. No patient had major adverse event. Five patients experienced minor side effects: mild chest pain/dyspnea in three, self-terminating atrial flutter in one, and decrease in blood pressure in one. Significant LV flow reserve was observed in 20 patients (40%). CONCLUSION: Low-dose dobutamine stress test appeared safe and feasible patients with high gradient aortic stenosis, and showed LV flow reserve in a minority of them.

Automatic measurement of aortic annulus diameter in 3-dimensional transoesophageal echocardiography.

BACKGROUND: Transcatheter aortic valve implantation involves percutaneously implanting a biomechanical aortic valve to treat severe aortic stenosis. In order to select a proper device, precise sizing of the aortic valve annulus must be completed. METHODS: In this paper, we describe a fully automatic segmentation method to measure the aortic annulus diameter in patients with aortic calcification, operating on 3-dimensional transesophageal echocardiographic images. The method is based on state estimation of a subdivision surface representation of the left ventricular outflow tract and aortic root. The state estimation is solved by an extended Kalman filter driven by edge detections normal to the subdivision surface. RESULTS: The method was validated on echocardiographic recordings of 16 patients. Comparison against two manual measurements showed agreements (mean ±SD) of -0.3 ± 1.6 and -0.2 ± 2.3 mm for perimeter-derived diameters, compared to an interobserver agreement of -0.1 ± 2.1 mm. CONCLUSIONS: With this study, we demonstrated the feasibility of an efficient and fully automatic measurement of the aortic annulus in patients with aortic disease. The algorithm robustly measured the aortic annulus diameter, providing measurements indistinguishable from those done by cardiologists.

Krill oil attenuates left ventricular dilatation after myocardial infarction in rats.

BACKGROUND: In the western world, heart failure (HF) is one of the most important causes of cardiovascular mortality. Supplement with n-3 polyunsaturated fatty acids (PUFA) has been shown to improve cardiac function in HF and to decrease mortality after myocardial infarction (MI). The molecular structure and composition of n-3 PUFA varies between different marine sources and this may be of importance for their biological effects. Krill oil, unlike fish oil supplements, contains the major part of the n-3 PUFA in the form of phospholipids. This study investigated effects of krill oil on cardiac remodeling after experimental MI. Rats were randomised to pre-treatment with krill oil or control feed 14 days before induction of MI. Seven days post-MI, the rats were examined with echocardiography and rats in the control group were further randomised to continued control feed or krill oil feed for 7 weeks before re-examination with echocardiography and euthanization. RESULTS: The echocardiographic evaluation showed significant attenuation of LV dilatation in the group pretreated with krill oil compared to controls. Attenuated heart weight, lung weight, and levels of mRNA encoding classical markers of LV stress, matrix remodeling and inflammation reflected these findings. The total composition of fatty acids were examined in the left ventricular (LV) tissue and all rats treated with krill oil showed a significantly higher proportion of n-3 PUFA in the LV tissue, although no difference was seen between the two krill oil groups. CONCLUSIONS: Supplement with krill oil leads to a proportional increase of n-3 PUFA in myocardial tissue and supplement given before induction of MI attenuates LV remodeling.

Left Ventricular Systolic Function in Long-Term Survivors of Allogeneic Hematopoietic Stem Cell Transplantation.

BACKGROUND: Allogeneic hematopoietic stem cell transplantation (allo-HSCT), a potentially curative therapy for malignant and nonmalignant diseases, is being increasingly used in younger patients. Although allo-HSCT survivors have an established increased risk of cardiovascular disease, there is limited knowledge of the long-term effects on cardiac function in survivors. OBJECTIVES: The purpose of this study was to describe left ventricular (LV) systolic function in long-term allo-HSCT survivors treated in childhood, adolescence, or early adulthood. METHODS: Our cross-sectional cohort study included 104 patients (56% women), age 18 ± 10 years at time allo-HSCT with 17 ± 6 years of follow-up. Echocardiography included 2-dimensional (2D) and 3-dimensional (3D) analyses and speckle tracking imaging. In total, 55 healthy control subjects with a similar age, sex, and body mass index were used for comparison. Left ventricular systolic dysfunction (LVSD) was defined as reduced 2D left ventricular ejection fraction (LVEF) of <52% in men and <54% in women, and/or a reduced global longitudinal strain (GLS) of ≥-17%. Multivariable linear regression was used to determine independent predictors of 2D-LVEF and GLS. RESULTS: Allo-HSCT survivors had significantly reduced LV systolic function compared with control subjects: 2D-LVEF (55.2 ± 5.8% vs. 59.0 ± 2.9%; p < 0.001), 3D LVEF (54.0 ± 5.1% vs. 57.6 ± 2.7%; p < 0.001), and GLS (-17.5 ± 2.2% vs. -19.8 ± 1.4%; p < 0.001). LVSD was found in 44.2%, of whom 28.3% were symptomatic. Clinical factors independently associated with 2D-LVEF and/or GLS included age, anthracyclines, graft versus host disease (GVHD), heart rate, and hypertension. In the 45% of survivors pre-treated with anthracyclines, the effect of anthracyclines on 2D-LVEF and GLS was dose-dependent. CONCLUSIONS: LVSD is common in long-term survivors of allo-HSCT treated in their youth. Pre-HSCT therapies with anthracyclines, age, heart rate, hypertension, and graft versus host disease are associated with measures of LV function.

Detection of intraoperative myocardial dysfunction by accelerometer during aortic valve replacement.

OBJECTIVES: Myocardial dysfunction may occur during weaning from cardiopulmonary bypass (CPB). Epicardial accelerometers have been shown to be useful in continuous monitoring of myocardial ischaemia during beating-heart surgery. We aimed to investigate whether an accelerometer can detect myocardial dysfunction during weaning from CPB. METHODS: In 23 patients undergoing isolated aortic valve replacement (AVR), a three-axis accelerometer was attached to the left ventricle and 3D velocity was calculated from the signals. Peak early systolic velocity (Vsys) and velocity at aortic valve closure (Vavc) were measured. Measurements were undertaken during normothermia with 50% bypass flow and atrial pacing (90 beats/min) before aortic cross-clamping and after cross-clamp removal. Myocardial dysfunction was defined as Vsys < Vavc, and patients were classified as having normal function or dysfunction. Left ventricular (LV) stroke work via pulmonary artery catheter and systolic velocity by echocardiography were compared between groups and used as reference methods. RESULTS: The accelerometer identified a substantial proportion of patients with myocardial dysfunction during weaning from CPB, 56% of patients compared with 11% before aortic cross-clamping. Patients classified with normal myocardial function during weaning significantly improved their LV stroke work and systolic velocity by echocardiography in response to AVR, whereas those classified with dysfunction did not. Accelerometer classification of normal function predicted an increase in echocardiographic systolic velocity [r = 0.63, regression coefficient 1.98, 95% CI (0.57, 3.40) (P < 0.01)]. CONCLUSIONS: The accelerometer detected myocardial dysfunction during weaning from CPB in accordance with measures obtained by echocardiography and pulmonary artery catheter. Clinical Trials identifier: NCT01926067. https://clinicaltrials.gov/.

Left ventricular function in long-term survivors of childhood lymphoma.

Survivors of childhood lymphoma (CL) have markedly increased risk of developing heart failure. Echocardiographic studies after cardiotoxic treatment have primarily demonstrated left ventricular (LV) systolic dysfunction. In the present study, we hypothesized that longer follow-up and a more comprehensive echocardiographic examination would reveal more cardiac abnormalities. We conducted a cross-sectional study with echocardiography 20.4 ± 8.6 years after diagnosis in 125 survivors of CL, grouped according to treatment methods, and compared with matched controls. Treatment included mediastinal radiotherapy (median 40.0 Gy) in 66 and anthracyclines (median dose 160 mg/m(2)) in 92 survivors of CL. Abnormal LV function, left-sided valve dysfunction, or both occurred in 62 patients (50%). Diastolic dysfunction occurred in 29%. Compared with control subjects, mitral annular early diastolic velocities (e') were reduced in patients (septal e' 0.09 ± 0.03 vs 0.12 ± 0.03 m/s, p <0.001), and the E/e' ratio was increased, particularly after mediastinal radiotherapy (10.6 ± 6.4 vs 5.6 ± 1.3, p <0.001). Survivors of CL had lower fractional shortening than control subjects (32 ± 6 vs 36 ± 7, p <0.001), but mean ejection fraction was equal and overt systolic dysfunction was infrequent. After mediastinal radiotherapy alone, global longitudinal myocardial strain was lower (p <0.05) compared with other treatment groups. Left-sided valvular dysfunction occurred in 55% of patients after mediastinal radiotherapy. In conclusion, survivors of CL had reduced LV diastolic function assessed by tissue Doppler imaging. This was more pronounced after mediastinal radiotherapy, which also frequently led to valvular disease. Systolic function was normal in most survivors of CL.