Patient selection and optimal timing for implantation are unsettled issues in candidates for a bridge to cardiac transplantation. A prospective evaluation of a strategy based on enoximone (E) given IV, in addition to sympathomimetic drugs, permitting to buy time, and delay by hours or days the decisions, has been performed from 1985 to 1988. Thirty-four patients in cardiogenic shock with hemodynamical criteria for TAH implantation have been included: Cl was 1.8 +/- 0.2 L/min/m2 PCWP 29 +/- 7 mmHg, diuresis less than 20 ml/hr. The protocol permitted to postpone decisions of implantation in 30 cases. The 4 unresponsive patients were implanted immediately with TAH (3) or VAD (1). Three were transplanted, two successfully. For 30, time given permitted discovery of hidden contraindications to transplantation in 17 patients. In 13, indication for transplantation was confirmed and performed in 11 within 6 hrs to 8 days (survival 64%). In two, sudden deterioration led to an unsuccessful TAH implantation. Multifactorial analysis showed that a 50% rise in Cl together with a 50% drop in PCWP, a 50% drop in PVR 30 min after IV E has a high predictive value of survival. These data suggest that enoximone IV bolus given in addition to maximal sympathomimetics to patients in cardiogenic shock reduces by 88% the need for TAH or VAD. It also permits a better selection of the candidates.

Adult↗

PubMedDate not supplied

The Mitroflow pericardial valve. First five years of follow-up evaluation.

The first 5 years durability study on a substantial number of Mitroflow pericardial valves makes the substance of the present report. One hundred eighty-eight valves were implanted on 166 patients before December 1985: 149 patients were discharged and are recalled annually. Follow up is 99% complete. In October 1988, mean follow up was 3.5 years (3-5.5). Total patients times years is 582. Sixty-two percent of the patients are asymptomatic, 58% in sinus rhythm. Forty-seven percent do not receive any anticoagulant therapy. The linearized rates of thromboembolism (1.2% per patient-year) and endocarditis (0.17 per patient-yr) is minimal. Seven patients only had valve dysfunction requiring explantation (1.2% per patient-yr). At 5 years, freedom of structural deterioration is 95.2% +/- 2.1. Single cusp tear at a stent post is the most frequent lesion (86%) as calcifications are observed in three only (major in two, microscopical in one). Histology does not permit to ascertain whether the tear is due to tissue fatigue or abrasion. Moderate microscopic architectural disruption of the valvular tissue is observed. Composite indices of all valve mortality and morbidity show at 5 years a 89.7% +/- 2.9 freedom of events. These data, associated to the high mechanical and optimal clinical characteristics of the valve, published previously, confirm the satisfactory performances of the valve at 5 years.

Adolescent↗

PubMedDate not supplied

An original inflow cannula for paracorporeal assist devices.

Cannulae for paracorporeal ventricular assist devices have been clinically shown to be limiting factors in optimal circulatory support. A new inflow cannula has been manufactured according to an original silicone rubber molding process, permitting a hemocompatible inner surface. The cannula is 200 mm in length, with a 10 mm internal diameter. The wall is 3 mm thick and reinforced by a stainless steel spiral spring embedded in the silicone. An external ring permits adequate interface between the cannula and the endocardial surface of the atrium. A compliant external segment on the inflow cannula, free of any spiral spring, allows adjustment of vacuum to optimal values, thus avoiding inflow obstruction. The cannula has been tested during 1 to 5 days of left ventricular bypass in calves (n = 15). A Symbion AVAD, Utah 85 VAD, or Centrimed pumps were used. Adequate heparinization was maintained throughout. Paracorporeal flow was 0.045 L min-1 kg-1. In vivo evaluation was made by hemodynamic studies and the incidence of thromboembolism. The cardiac cavities, cannulae, and peripheral vessels were carefully searched for thrombi and emboli at autopsy. The atrium, the interface between atrium and silicone cannula, and the cannula itself were found free of any deposit. This aspect differed from that observed previously with available PU or PVC cannulae.

Animals↗

PubMedDate not supplied

Assessment of a percutaneous Hemopump in high risk coronary angioplasty patients.

This study assessed the safety and efficacy of a new 14 Fr Hemopump device. Ten high risk patients requiring percutaneous transluminal coronary angioplasty (PTCA) (last remaining patent vessel or low left ventricular ejection fraction) underwent PTCA with the prophylactic use of the Hemopump. This device was inserted percutaneously through the femoral artery using a 16 Fr sheath and placed into the left ventricle. Hemodynamic parameters (pulmonary capillary wedge pressure, cardiac output, mean aortic pressure) were recorded before, during, and after PTCA when the Hemopump was on and off. Adequate placement of the Hemopump was obtained in all patients with moderate temporary rhythm instability, and PTCA was performed in all patients. Under assist, pulmonary capillary wedge pressure was 22 +/- 8 mmHg, compared with 29 +/- 7 mmHg (P < 0.05), whereas no significant change in other hemodynamic parameters was observed. One patient experienced ventricular fibrillation twice during PTCA, which was correlated by electrical cardioversion. During this temporary cardiac arrest, the aortic blood pressure was maintained at 50 mmHg with the Hemopump. For all patients, the Hemopump was withdrawn 15 min after the end of PTCA, and the sheath was removed 4-6 hr later. However, two patients required surgical sheath removal. One patient died of cardiogenic shock in the intensive care unit. Other patients were discharged 3 days after the procedure. Long-term follow-up shows eight surviving patients. These data show that 1) the 14 Fr percutaneous Hemopump is safe, and 2) can unload the left ventricle during PTCA while maintaining mean aortic pressure and cardiac output.

Aged↗

PubMedDate not supplied

Deterioration of bioprosthetic heart valves.

The aim of this study was to detect biologic factors in the structural deterioration of bioprosthetic heart valves. Prostheses were removed from patients after 4-8 years of implantation and submitted to biochemical and morphologic assays. Successive staining of biologic sections revealed colocalization of lipids and glycosaminoglycans underneath calcifications in the disintegrated extracellular matrix. On biochemical assays, the amidolysis of synthetic peptide substrates indicated thrombin, plasmin, and tissue plasminogen activator activities in the nonhemocompatible leaflets; 0.15 mol NaCl, 0.05 mol Tris, and 5 mmol CaCl2 extracts from the prostheses cleaved the peptide substrate for collagenase and lysed gelatin gels. Polyacrylamide gel electrophoresis in sodium dodecyl sulfate disclosed the presence of low molecular mass polypeptides in extracts of the deteriorated prostheses. The detection of plasmin and collagenolytic enzyme(s), and the known broad proteolytic activity of plasmin, may point to the role of activation of the fibrinolytic system in the proteolytic degradation of bioprosthetic valves.

Animals↗