How reliable is an effective orifice area indexed chart?

BACKGROUND AND AIM OF THE STUDY: Patient-prosthesis mismatch (PPM) occurs when a valvular prosthesis is too small relative to the patient's body surface area (BSA). The presence of PPM results in increased transprosthetic gradients and may portend a worse prognosis. It has been shown that reliable effective orifice area (EOA) data can be used to accurately predict PPM, thus preventing its occurrence. The study aim was to assess the predictive abilities of an effective orifice area indexed (EOAI) chart--the Perimount Magna EOAI chart--in the prevention of PPM. METHODS: A retrospective comparison of projected versus calculated EOA values and the predicted versus actual incidence of PPM was conducted. Forty patients with a Perimount Magna aortic bioprosthesis implanted between 1st January 2006 and 31st March 2009, were identified. The sensitivity, specificity, positive-predictive value (PPV) and negative predictive value (NPV) were each calculated using the Perimount Magna EOAI chart, to assess how well it could predict the incidence of postoperative PPM. RESULTS: The Perimount Magna EOAI chart had a sensitivity of 35% for predicting postoperative PPM, and an NPV of 53%. The projected EOA-values were almost invariably larger than those actually measured; this resulted in a higher proportion of patients than in whom PPM was predicted preoperatively. This EOAI chart proved to be very specific, with specificity of 100% and a PPV of 100%. CONCLUSION: The Perimount Magna EOAI chart, based on mean EOA data from a small echocardiographic cohort, represents a poor method of predicting and preventing PPM. Rather, EOAI charts should be based on reliable EOA data that reproducibly predict the expected EOA for that prosthesis.

The use of the mini-cardiopulmonary bypass circuit in robotic mitral valve surgery.

BACKGROUND: : Computer enabled robotic mitral valve repair cases have longer cross-clamp and perfusion times because of the more technically difficult procedure. To modify some of the well-documented side effects of standard cardiopulmonary bypass (CPB), we used a new mini-circuit on three robotic mitral cases. METHODS: : Three patients having mitral valve repair (triangular resection of P2 and annuloplasty ring) using the daVinci Robot (Intuitive Surgical, Sunnyvale, CA) had circulatory support using a modified Resting Heart System (Medtronic, Inc., Fridley, MN), a vertically oriented space saving CPB configuration incorporating a high efficiency miniaturized oxygenator, centrifugal pump, shortened heparin coated tubing and an air evacuation system with a closed circuit. RESULTS: : All patients had successful mitral repair (echo = 0 to trace residual leakage) under a cross-clamp time of 161 ± 54 minutes and perfusion time of 229 ± 31 minutes. No blood was given during CPB and 0.7 ± 1.2 red cell units after the CPB run and 0.7 ± 1.2 units during the postoperative course. CONCLUSION: : Miniaturized bypass circuit reducing the level of necessary anticoagulation, hemodilation, and blood trauma can be used despite the increased perfusion time necessary for robotic mitral surgery.

Anticoagulation for mechanical heart valves: a role for patient based therapy.

Anticoagulation management issues following mechanical cardiac valve replacement revolve around target levels for chronic oral anticoagulation. While these levels are important, they are only one aspect of a follow-up process that should be individualized to each patient with a mechanical cardiac valve and coupled with patient education, risk factor modification, and long-term follow-up. It is difficult to separate patient related risk factors, those traditional risk factors that markedly increase the incidence of potential valve related events (i.e., atrial fibrillation), and yet other more subtle non-traditional risk factors for thromboembolism (i.e., smoking and hypertension) that contribute to events. These also require management during the post-operative period and long-term follow-up. There are also different risk factors for anatomic valve position. The aortic valve is the safest of all the anatomic positions regarding valve related events. The mitral valve is at higher risk and the tricuspid valve is the most risky anatomic position. Anticoagulation related hemorrhage is the most dangerous event for mortality and morbidity in the aortic position, thromboembolism in the mitral position, and valve thrombosis in the tricuspid position. Each of these requires different degrees of patient modification and target levels for anticoagulation. Additionally, low risk patients with aortic valve replacement may not require anticoagulant therapy at all. Rather, treatment with modern, highly potent platelet inhibiting drugs may be effective after a period of sewing ring endothelialization under the protection of antithrombotic therapy. Each of these aspects and risk factors is discussed, as well as the call for prospective randomized trials treating low risk patients with anti-platelet drugs versus warfarin anticoagulation.

The St. Jude Medical cardiac valve prosthesis: long-term follow up of patients having double valve replacement.

BACKGROUND AND AIM OF THE STUDY: Between October 1977 and February 2002, a total of 343 patients (mean age 62 +/- 13 years; range: 19-91 years) underwent double valve replacement (DVR) with the St. Jude Medical (SJM) heart valve. Among the replacements, 337 (98%) were aortic and mitral in nature. Concomitant coronary artery bypass was performed in 73 patients (21%). METHODS: Cardiac Surgical Associates has maintained an independent database of patients undergoing valve replacement with the SJM prosthesis since the valve's first implantation in October 1977. Patients were contacted by questionnaire and/or telephone (94% complete) between November 2002 and June 2003. The patients' hospital course and valve-related events were verified by patient chart review and/or physician contact. RESULTS: Operative mortality was 8% (n = 29); mortality was valve-related in two cases. The mean follow up was 6.5 +/- 6.0 years (range: 1 month to 24 years); total follow up was 2,226 patient-years. Over 25 years, patient freedom from late mortality was 62%, and from valve-related mortality 78%. Freedom from thromboembolic events was 82% (93% from permanent defect), from bleeding events 76%, from endocarditis 98%, from valve thrombosis 99.9%, and from reoperation 98%. Six reoperations were carried out in five patients (2%), valve repair or replacement in five (2%), and suture closure of paravalvular leak in one patient (0.3%). There were no valve structural failures reported. CONCLUSION: The SJM valve has proven to be an effective and durable heart valve prosthesis. Over the long-term, the event rate is low and there is excellent freedom from reoperation in the double valve configuration.

Use of peripheral ultrafiltration in the postoperative cardiac surgery patient.

BACKGROUND: : After cardiac surgery, most patients have development of third-space fluid retention, commonly treated with diuretics. In some patients diuretics are ineffective. In this subset, a simplified system for ultrafiltration was used for fluid extraction. METHODS: : After obtaining permission from the institutional review board, the hospital charts of the first 30 patients having ultrafiltration were retrospectively reviewed to abstract data on fluid extraction and patient outcomes. Data are expressed as mean ± standard deviation. RESULTS: : From April 2004 through January 2006, 30 patients were selected for ultrafiltration. In one patient, adequate intravenous access could not be obtained. There were 11 female and 18 male (age, 69 ± 12 years) postoperative cardiac surgery patients. The mean ultrafiltration run was 10.5 ± 9 hours, resulting in fluid extraction of 3528 ± 2111 mL per run and 5596 ± 3870 mL per patient (11 patients had more than 1 run). Hospital stay was 9.4 ± 4.4 days. Three patients died unrelated to ultrafiltration. CONCLUSIONS: : Ultrafiltration as an alternative means of fluid extraction in postoperative cardiac surgery patients was effective and well tolerated.