MitraClip for radiotherapy-related mitral valve regurgitation.

OBJECTIVE: Owing to mediastinal and cardiac damage burden, the surgical treatment of radiotherapy-related mitral regurgitation (MR) may be associated with high operative risk or might even contraindicated. We evaluated the feasibility and outcome of MitraClip therapy in patients with radiotherapy-related MR as an alternative to surgery. METHODS: Based on Doppler Echocardiography, 15 of 33 screened patients underwent MitraClip implantation. RESULTS: Following MitraClip MR improved (residual MR ≤2+) without significant mitral valve stenosis (planimetric area 2.83 ± 0.8 cm2, mean gradient 4.6 ± 1.8 mm Hg). All patients completed a 6-month follow-up, while 14 of 15 patients achieved a longer follow-up, ranging from 12 to 72 months (median 24 months, IQR 42 months). At 6-month follow-up we observed NYHA improvement in 13 patients with an increase of 6-min walking covered distance (from 260 ± 34 to 367 ± 70, p < 0.001), sustained moderate or less MR, mild mitral stenosis in 3 patients, and significant systolic Pulmonary Artery Pressure (PAPs) reduction (from 52.5 ± 14 to 42 ± 9, p < 0.01). Sustained clinical improvement and ≤2+ MR was observed in 13 of 14 patients who completed the 12-month follow-up. Two patients died of acute pneumonia (11 months and 60 months, respectively). One patient developed moderate MV stenosis (MVA 1.4 cm2) at last follow-up (48 months) without related clinical instability. Tricuspid regurgitation improved in 12 patients with further improvement at late follow-up in 2 of 3 patient with 3+. CONCLUSION: MitraClip may be an effective treatment for RT-induced MR, although unexpected late stenosis may occur in the context of sustained reactive mitral apparatus damage following mediastinal radiation.

Risk of valvular heart disease after treatment for Hodgkin lymphoma.

BACKGROUND: Hodgkin lymphoma (HL) survivors are at increased risk of developing valvular heart disease (VHD). We evaluated the determinants of the risk and the radiation dose-response. METHODS: A case-control study was nested in a cohort of 1852 five-year HL survivors diagnosed at ages 15 to 41 years and treated between 1965 and 1995. Case patients had VHD of at least moderate severity as their first cardiovascular diagnosis following HL treatment. Control patients were matched to case patients for age, gender, and HL diagnosis date. Treatment and follow-up data were abstracted from medical records. Radiation doses to heart valves were estimated by reconstruction of individual treatments on representative computed tomography datasets. All statistical tests were two-sided. RESULTS: Eighty-nine case patients with VHD were identified (66 severe or life-threatening) and 200 control patients. Aortic (n = 63) and mitral valves (n = 42) were most frequently affected. Risks increased more than linearly with radiation dose. For doses to the affected valve(s) of less than or equal to 30, 31-35, 36-40, and more than 40 Gy, VHD rates increased by factors of 1.4, 3.1, 5.4, and 11.8, respectively (P trend < .001). Approximate 30-year cumulative risks were 3.0%, 6.4%, 9.3%, and 12.4% for the same dose categories. VHD rate increased with splenectomy by a factor of 2.3 (P = .02). CONCLUSIONS: Radiation dose to the heart valves can increase the risk of clinically significant VHD, especially at doses above 30 Gy. However, for patients with mediastinal involvement treated today with 20 or 30 Gy, the 30-year risk will be increased by only about 1.4%. These findings may be useful for patients and doctors both before treatment and during follow-up.

Transient severe reversible functional mitral regurgitation: a three-dimensional transoesophageal perspective.

Mrs B, a 49-year-old female, was referred to our institution for severe mitral regurgitation. Transthoracic echocardiography showed only a moderate organic mitral regurgitation, but a transient severe reversible functional mitral regurgitation was observed during transoesophageal echocardiography (TEE). Three-dimensional TEE clearly demonstrated the functional nature of the regurgitation with a transient and sudden tenting of the mitral leaflets with a circular mitral annulus resulting in a total absence of leaflet coaptation.

Valvular dysfunction and left ventricular changes in Hodgkin's lymphoma survivors. A longitudinal study.

PURPOSE: Hodgkin's lymphoma survivors (HLSs) have an elevated risk for cardiovascular diseases that appear several years after radiotherapy. This study examined the time-dependent development and evolution of valvular and myocardial function related to treatment with mediastinal radiotherapy and anthracyclines in HLSs. PATIENTS AND METHODS: In 1993, echocardiography was performed in 116 HLSs median 10 years (range 6-13 years) after treatment with mediastinal radiotherapy. None of the 116 patients had valvular stenosis in 1993 whereas 36 (31%) had moderate valvular regurgitation. In 2005-2007, 51 of 57 invited patients were included in a second echocardiographic study - median 22 years (range 11-27 years) after treatment. Of these patients, 28 (55%) had also received anthracyclines. The patients were selected on the basis of the presence or absence of moderate valvular regurgitation in 1993. RESULTS: The second echocardiographic study demonstrated that 10 out of 27 (37%) patients with only mild or no aortic or mitral regurgitation in 1993 had developed moderate regurgitation in either or both the aortic or mitral valve. Of the 24 patients with moderate (n=23) or severe (n=1) regurgitation in the aortic or mitral valve in 1993, 8 (33%) had progressed to severe regurgitation, developed moderate regurgitation in a previously normal or mild regurgitant valve or had received valvular replacement. In total, of all patients, 20 (39%) had developed mild to severe aortic stenosis and 3 patients had received valvular replacement. In a multiple linear regression the use of anthracyclines predicted left ventricular remodelling between ECHO 1993 and 2005 as demonstrated by increased left ventricular end systolic diameter (beta =0.09 (95% CI 0.01-0.17), P=0.04) and reduced thickness of the left ventricular posterior wall (beta =-0.18 (95% CI -0.33 to -0.03), P=0.02) and interventricular septum (beta =-0.16 (95% CI -0.30 to -0.03), P=0.02). CONCLUSION: Given the progressive nature of valvular dysfunction and left ventricular remodelling 20-30 years after diagnosis, we recommend life-long cardiological follow-up of HLSs treated with mediastinal radiotherapy.

Estimating 241Am activity in the body: comparison of direct measurements and radiochemical analyses.

The assessment of dose and ultimately the health risk from intakes of radioactive materials begins with estimating the amount actually taken into the body. An accurate estimate provides the basis to best assess the distribution in the body, the resulting dose and ultimately the health risk. This study continues the time-honoured practice of evaluating the accuracy of results obtained using in vivo measurement methods and techniques. Results from the radiochemical analyses of the (241)Am activity content of tissues and organs from four donors to the United States Transuranium and Uranium Registries (USTUR) were compared with the results from direct measurements of radioactive material in the body performed in vivo and post-mortem. Two were whole-body donations and two were partial-body donations. The (241)Am lung activity estimates ranged from 1 to 30 Bq in the four cases. The (241)Am activity in the lungs determined from the direct measurements were within 40% of the radiochemistry results in three cases and within a factor of 2 for the other case. However, in one case the post-mortem direct measurement estimate was a factor of 10 higher than the radiochemistry result for lung activity, most probably due to underestimating the skeletal contribution to the measured count rate over the lungs. The direct measurement estimates of liver activity ranged from 2 to 60 Bq and were consistently lower than the radiochemistry results. The skeleton was the organ with the highest deposition of (241)Am activity in all four cases. The skeletal activity estimates ranged from 30 to 300 Bq. The skeletal activity obtained from measurements over the forehead were within 20% of the radiochemistry results in three cases and differed by 78% in the other case. The results from this study suggest that the measurement methods, data analysis methods and calibration techniques used at the In Vivo Radiobioassay and Research Facility can be used to quantify the activity in the lungs, skeleton and liver when (241)Am activity is present in all three organs. The adjustment method used to account for the contribution from activity in other organs improved the agreement between the direct measurement results and the radiochemistry results for activity in the lungs and skeleton. The method appeared to overestimate the contribution from the other organs to the liver activity measurements, although the low activity levels complicated the analysis. The unadjusted liver activity estimates from the direct measurements were generally in better agreement with the radiochemistry results than the adjusted liver activity. The data from this study indicates that the results from the in vivo measurement techniques provide reasonable estimates of radioactive material in the lungs and skeleton under the most challenging conditions where there is (241)Am activity in multiple organs. The data analysis from additional USTUR cases with both direct measurement results and radiochemistry results is in progress to further evaluate how best to account for the contributions from (241)Am activity in multiple organs and to better understand the uncertainty associated with the adjusted activity.

Radiation-associated valvular heart disease in Hodgkin's disease is associated with characteristic thickening and fibrosis of the aortic-mitral curtain.

Radiation-associated valvular dysfunction is characterized by variable aortic and mitral valve thickening. A review of three patients assessed echocardiographically revealed that radiation-associated valvular dysfunction after radiation treatment for Hodgkin's disease may be characterized by a unique and consistent pattern of thickening of the aortic and mitral valves involving the aortic-mitral curtain.

Surgical management of radiation-induced heart disease.

BACKGROUND: With the increasing population of patients with prior mediastinal irradiation, cardiac surgeons will encounter patients with radiation-induced damage to the heart and the great vessels. Awareness of the pathology and the surgical management is essential to provide optimal care for these patients. METHODS: Eight patients with radiation-induced heart disease were encountered in the last 10 years. After a brief clinical presentation, the surgical management of radiation-induced heart disease is reviewed. RESULTS: Radiation can affect all the structures in the heart, including the coronary arteries, the valves, and the conduction system. The pericardium is the most commonly involved, and the conduction system is the least involved. Pericardiectomy is quite effective in patients with symptomatic pericardial effusion or constriction. The coronary lesions are located predominantly in the ostial or proximal regions of the epicardial vessels. Percutaneous transluminal coronary angioplasty alone appears to have a high rate of restenosis. Surgical revascularization has good long-term results, and the internal mammary artery should be used if it is satisfactory. The aortic and mitral valves are more commonly involved than the tricuspid and pulmonary valves. Myocardial dysfunction predominantly affects the right ventricle and requires particular attention during cardiopulmonary bypass and in the postoperative period. Restoration of sinus rhythm is essential in view of stiffness of the ventricles. Flexibility in the surgical approach with selective use of thoracotomy will facilitate the surgical procedure in certain patients. CONCLUSIONS: Surgeons should be well versed in all the manifestations and the management of radiation-induced heart disease.

Severe mitral regurgitation caused by immobile posterior leaflet after radiotherapy.

Radiotherapy may affect the heart in several ways. We describe a child who had pulmonary edema caused by severe mitral regurgitation after thoracic radiotherapy for a Ewing sarcoma. Transesophageal echocardiography demonstrated this to be caused by an immobilized posterior leaflet, and valve replacement was necessary. This is the first reported patient with rapid progression to severe valvar disease after radiotherapy and in whom this novel mechanism has been demonstrated.