Economic evaluation of an ultra-high density mapping system compared to non-ultra-high density mapping systems for radiofrequency catheter ablation procedures in patients with atrial fibrillation.

PURPOSE: Advanced non-fluoroscopic mapping systems for radiofrequency ablation (RFA) have shown to be an effective treatment of atrial fibrillation. This study analyzes the resource usage and subsequent costs associated with the implementation of an ultra-high density mapping system (UHDMS) compared to non-ultra-high density mapping systems (NUHDMS). METHODS: This retrospective observational study included 120 patients (18 years or older) with paroxysmal or persistent atrial fibrillation who underwent RFA for de novo pulmonary vein isolation guided either by an UHDMS (n=63) or NUHDMS (n=57) for their index procedure. We compared patient characteristics, short- and long-term procedural outcomes, resource usage, and clinical outcomes followed up to 16 months between the two treatment groups. The cost analysis was conducted from the perspective of a single center in Spain (Clinica Universidad de Navarra). RESULTS: Neither baseline patient characteristics nor complication rate differed between groups. Repeat RFAs following recurrent arrhythmia at 16 months was lower in the UHDMS patient group than in the NUHDMS group (6 vs. 14, respectively; P=0.027). The average total cost per patient was €1,600 lower in the UHDMS group, compared to the NUHDMS group (€11,061 and €12,661, respectively; P=0.03). CONCLUSION: In patients treated with an NUHDMS, 25% had a repeat ablation for recurrent arrhythmia, whereas only 9% of patients treated with a UHDMS had one (61% relative risk reduction), resulting in an average cost saving per patient of €1,600.

Effect of mechanical aortic valve orientation on coronary artery flow: comparison of tilting disc versus bileaflet prostheses in pigs.

OBJECTIVE: Orientation for optimal systolic performance of tilting disc and bileaflet aortic valves was defined in previous studies. The present study investigates the influence of valve orientation on coronary artery flow in an animal model. METHODS: A rotation device holding either a Medtronic Hall tilting disc (n = 4; Medtronic, Inc, Minneapolis, Minn), a St Jude Medical bileaflet (n = 4; St Jude Medical, Inc, St Paul, Minn), or a Medtronic Advantage bileaflet (n = 3) aortic valve was implanted. The device allowed rotation of the valve without reopening the aorta. Flow through the left anterior descending coronary artery was measured preoperatively and at normal versus high cardiac output after weaning from extracorporeal circulation. Measurements were performed at the best and worst hemodynamic position, as defined previously. RESULTS: Coronary flow rates were similar in all animals preoperatively (26 +/- 4.1 mL/min). After aortic valve replacement, left anterior descending flow increased significantly to 58.2 +/- 10.6 mL/min. Highest flow rates at normal cardiac output were found in the optimum orientation, especially for the Medtronic valves (Medtronic Hall, 64 +/- 8.7 mL/min; Medtronic Advantage, 64.6 +/- 11.6 mL/min; St Jude Medical, 48.3 +/- 10.3 mL/min), whereas the worst position demonstrated significantly lower left anterior descending flow, with no differences among valves (Medtronic Hall, 37.5 +/- 1.3 mL/min; St Jude Medical, 35.7 +/- 10.7 mL/min; Medtronic Advantage, 39.8 +/- 10 mL/min). Left anterior descending artery flow increased significantly with higher cardiac output. CONCLUSIONS: Coronary blood flow was significantly influenced by mechanical aortic valve implantation and the orientation of prostheses. For both valve designs, the previously defined optimum orientation with respect to pressure gradients and turbulence demonstrated the highest left anterior descending flow rates. Even in its optimum orientation, the St Jude Medical valve showed significantly lower coronary flow than the other valves.

Comparison of hemodynamic performance of Medtronic Hall 21 mm versus St. Jude Medical 23 mm prostheses in pigs.

BACKGROUND AND AIM OF THE STUDY: The ideal prosthesis for aortic valve replacement in the small annulus remains controversial, and has yet to be defined. In previous studies, the Medtronic Hall (MH) tilting disc valve showed superior hemodynamic performance in the hemodynamically optimum orientation compared to the St. Jude Medical (SJM) bileaflet valve, especially in smaller-sized valves. Using an animal model, the hemodynamics of 21 mm MH and 23 mm SJM valves, both of which have shown identical performance in previous clinical studies, were compared. METHODS: A rotation device holding either a MH or a SJM aortic valve was implanted into eight pigs. The device allowed rotation of the implanted valve without reopening the aorta. In different orientations (best and worst orientation hemodynamically as defined previously), transvalvular pressure gradients and ventricular dimensions were measured using transesophageal echocardiography at constant hemodynamic conditions. RESULTS: In the optimum hemodynamic orientation, pressure gradients of the MH valve (6.3+/-1.7 mmHg) corresponded to those obtained with the SJM valve (6.3+/-3.7 mmHg), whereas in the worst orientation the MH showed a tendency towards higher gradients (14.0+/-2.9 versus 10.3+/-4.0 mmHg) (p = not significant). A significant increase in left ventricular enddiastolic diameter was observed for both valve designs with rotation from the optimal into the worst orientation. CONCLUSION: In the optimum hemodynamic orientation, the 21 mm MH valve matched the hemodynamic performance of the 23 mm SJM valve. Thus, implantation of the MH valve might be an alternative to root enlargement and implantation of a larger SJM valve in patients with a small aortic annulus, though optimum orientation is required.

Successful treatment of deep sternal infections following open heart surgery by bilateral pectoralis major flaps.

OBJECTIVES: Severe sternum necrosis requiring extended resection necessitates plastic reconstruction of the resulting defect and stabilization of the chest. We analyzed the outcome of patients undergoing bilateral pectoralis major flap repair on functional and cosmetic results, chest stabilization and pulmonary function. METHODS: Twelve patients undergoing cardiac surgery between 1997 and 2001 suffered from a deep mediastinal wound infection and sternum necrosis. After a mean of two attempts of extensive wound debridement, all 12 patients underwent complete sternal resection with plastic reconstruction by bilateral pectoralis major flaps. Risk factors were obesity (n=10) and diabetes (n=11). Six months postoperatively patients underwent physical examination, pulmonary function testing and functional CT scan. RESULTS: Three patients died in hospital (two septic multiorgan failure, one heart failure) and nine were discharged with complete wound closure. One patient suffered a lethal stroke during follow-up. At 6-month follow-up no recurrent sternum infection had occurred. Chest stability was satisfactory without impairment of pulmonary function (VC 77.5+/-12.1% at follow-up vs 77.8+/-12.5% preoperatively). Mobility and force of arms and shoulder were adequate; at CT scan the maximum distance change between the former sternoclavicular joint in inspiration versus expiration was minimal. Quality of life questionnaires showed no significant limitations except a disturbed sleep and mild restriction of executing hobbies and social activities. CONCLUSIONS: Bilateral pectoralis major flap repair is a safe technique to cure severe mediastinitis necessitating complete sternal resection. Wounds close without extensive reconstructive surgery. Cosmetic results as well as stabilization of the chest were good. Patients reported an almost uncompromised quality of life without respiratory impairment.

Health services research in heart failure patients treated with a remote monitoring device in Germany-a retrospective database analysis in evaluating resource use.

OBJECTIVES: Heart failure is an increasing burden for all healthcare systems with prevalence reaching over 20 million patients worldwide and direct costs of disease requiring ∼1% of healthcare budget expenditures. Beyond traditional pharmaceutical treatment, medical devices and remote monitoring tools were introduced to ensure a closely managed control of patients. In this context, a decision-maker needs to know whether the new technology provides clinical benefit towards patients and what resource use is attached to them. METHODS: Health services research is a complementary approach to clinical trials providing results to the impact of the technology in real life settings. As an example this study reports of a secondary data analysis of one of the largest health insurance companies in Germany, comparing resource use of heart failure patients receiving a cardiac resynchronization therapy (CRT) device coupled with a fluid status monitoring and alert function with patients receiving conventional CRT, ICD (implantable cardioverter defibrillator), or no intervention. RESULTS: Disease-associated expenses can be attributed to far more than 50% to heart failure. Although implementation of the CRT device with alert function was most expensive (31,794 Euros compared to 27,659 Euros in the conventional CRT group, 24,128 Euros in the ICD group, and 3735 Euros in the no intervention group) in the first year after implementation, the least costs have been caused in this group (7000 Euros compared to more than 11,000 Euros in all other groups). CONCLUSION: This article highlights potential health services research approaches focusing on the example of a CRT device coupled with a pulmonary diagnostic and alert function. Although this retrospective analysis holds a number of limitations (e.g., small number of patients in intervention group, cost calculations only from the payer perspective), and despite the need for randomized controlled trials, it was shown that secondary data research in this field is a valuable approach.

Initial in vivo results of the new Medtronic Advantage(TM) bileaflet valve in aortic position and comparison to the SJM.

The present study investigated the Medtronic Advantage (MA) bileaflet valve in an animal model and compared the results to the St. Jude Medical (SJM) valve. Systolic performance and coronary artery flow in different orientations were studied.A rotation device holding either a MA or SJM aortic valve size 23 mm was implanted into eight pigs. Transvalvular pressure gradients and ventricular dimensions were investigated with the valves in different orientations. Coronary artery flow was measured at normal and high cardiac output. Orientation significantly influenced the hemodynamic performance of both valves. The best results for both valves were obtained with one orifice proximal to the right cusp. Pressure gradients and ventricular dimensions of the MA corresponded to the SJM. Coronary artery flow was higher for the MA. The systolic performance of the new MA bileaflet valve was similar to the SJM. During diastole, the MA showed significantly higher LAD coronary flow.