Autologous pericardium annuloplasty: a "physiological" mitral valve repair.

AIM: Autologous pericardium annuloplasty (APA) is an alternative to prosthetic ring implantation for mitral valve (MV) repair, avoiding the use of foreign material and preserving the mitral annulus' physiological motion. However, data on durability are questionable. Therefore, we analyzed long-term outcomes of treating degenerative mitral regurgitation (MR) with APA. METHODS: Four hundred ninety patients (mean age, 54.3±11.3 years, [15-77 years]; N.=360 men [74.1%]) who had undergone APA and neochordae implantation between July 1988 and December 2006 were retrospectively studied. RESULTS: MR was purely degenerative in 434 (89.3%) patients; endocarditis was present in 44 (9.1%) patients; an anterior, posterior, or bileaflet prolapse was present in 32 (6.6%), 241 (49.6%), and 213 (43.8%) patients, respectively. Clinical follow-up was 100% complete at a median of 6.5 years (5th percentile, 0.9; 95th percentile, 14.9) with an echocardiographic study in 92% of patients. In-hospital mortality was 1% (5 deaths); overall and late cardiac mortality were 7.6% and 3.9% (37 and 19 deaths), respectively. Kaplan-Meier curves for overall survival, late cardiac survival, and freedom from reoperation at 15 years (20 cases) were 86% (95%CI 80-91), 93% (95%CI 88-96), and 93% (95%CI 88-96), respectively. At 15 years, freedom from recurrent MR (28 patients) and endocarditis (6 events) were 86% (95%CI 76-91) and 97% (95%CI 92-99). Dehiscence, significant calcification of APA, and hemolysis never occurred. At reoperations, annular pericardium appeared covered by a smooth layer of tissue. CONCLUSION: APA is feasible, safe, and cost-effective, providing long-term durability, high survival, and a low rate of valve-related complications.

Preliminary evidence for reduced preoperative cerebral blood flow velocity as a risk factor for cognitive decline three months after cardiac surgery: an extension study.

This extension study investigated the association between preoperative cerebral blood flow (CBF) velocity and postoperative cognitive decline (POCD) at a three-month follow-up in patients who underwent cardiac surgery. Continuous transcranial Doppler ultrasound on both middle cerebral arteries (MCAs) was used preoperatively in 31 right-handed cardiac surgery patients at rest. Each patient performed a neuropsychological evaluation to assess cognitive performance before surgery, at discharge and at three-month follow-up. Patients with POCD at the three-month follow-up had a marginally significantly lower preoperative CBF velocity in the left MCA than patients without POCD. Moreover, the group with POCD had a significantly lower CBF velocity in the left than in the right MCA, whereas no difference between the left and right CBF velocity was found in the group without POCD. These preliminary findings suggest that reduced preoperative CBF velocity in the left MCA may represent an independent risk factor for cognitive decline in patients three months after surgery.

The importance of myocardial amino acids during ischemia and reperfusion in dilated left ventricle of patients with degenerative mitral valve disease.

Taurine, glutamine, glutamate, aspartate, and alanine are the most abundant intracellular free amino acids in human heart. The myocardial concentration of these amino acids changes during ischemia and reperfusion due to alterations in metabolic and ionic homeostasis. We hypothesized that dilated left ventricle secondary to mitral valve disease has different levels of amino acids compared to the right ventricle and that such differences determine the extent of amino acids' changes during ischemia and reperfusion. Myocardial concentration of amino acids was measured in biopsies collected from left and right ventricles before cardioplegic arrest (Custodiol HTK) and 10 min after reperfusion in patients undergoing mitral valve surgery. The dilated left ventricle had markedly higher (P < 0.05) concentrations (nmol/mg wet weight) of taurine (17.0 +/- 1.5 vs. 10.9 +/- 1.5), glutamine (20.5 +/- 2.4 vs. 12.1 +/- 1.2), and glutamate (18.3 +/- 2.2 vs. 11.4 +/- 1.5) when compared to right ventricle. There were no differences in the basal levels of alanine or aspartate. Upon reperfusion, a significant (P < 0.05) fall in taurine and glutamine was seen only in the left ventricle. These changes are likely to be due to transport (taurine) and/or metabolism (glutamine). There was a marked increase in the alanine to glutamate ratio in both ventricles indicative of ischemic stress which was confirmed by global release of lactate during reperfusion. This study shows that in contrast to the right ventricle, the dilated left ventricle had remodeled to accumulate amino acids which are used during ischemia and reperfusion. Whether these changes reflect differences in degree of cardioplegic protection between the two ventricles remain to be investigated.

Automated protamine dose assay in heparin reversal management after cardiopulmonary by pass.

BACKGROUND: To evaluate the impact of automated Protamine Dose Assay (PDA) performed with Hemochron 8000 (International Technodyne Company, Edison, NJ) on the management of heparin reversal after cardiopulmonary bypass (CPB). PDA was compared with empirical protamine to heparin ratio with regard to calculation of the protamine dose, and the sensitivity of PDA and ACT to residual circulating heparin after protamine administration was investigated too. DESIGN: prospective and randomized study. SETTING: cardiac surgical center of a General Hospital. PARTICIPANTS: 50 patients undergoing elective cardiac surgery with CPB. INTERVENTIONS: after CPB patients randomly received protamine according to our standard empirical ratio of 1 mg. protamine/100 U. heparin (group S, 24 patients), or to PDA result (group T, 26 patients) based on protamine titration method of determining circulating heparin. After protamine administration ACT and PDA were performed to assess heparin reversal and detect residual circulating heparin. Based on the PDA result, additional protamine was administered in both groups when required. MEASUREMENTS: in both groups basal and post-heparin ACT values, protamine doses, ACT and PDA after protamine administration were measured. RESULTS: The protamine dose was significantly lower (30%) in patients treated according to PDA. In 20% of patients showing normal ACT PDA revealed still circulating heparin, and additional protamine was required. In all other cases ACT and PDA both confirmed heparin reversal. CONCLUSIONS: PDA allowed us to administer a significantly lower amount of protamine. This can reduce incidence of adverse effects of over- and under-infusion of protamine. PDA also proved to be more sensitive than ACT in detecting residual circulating heparin after protamine administration.

Influence of transesophageal echocardiography on intraoperative decision making for toronto stentless prosthetic valve implantation.

BACKGROUND AND AIM OF THE STUDY: Intraoperative transesophageal echocardiography (TEE) is commonly used during aortic valve surgery. In aortic valve replacement (AVR), this permits measurement of the aortic annulus, study of the anatomy of aortic valve components, and prediction of prosthesis valve size. After cardiopulmonary bypass (CPB), echocardiography is valuable in checking prosthesis function. In this study, we evaluated the impact of intraoperative TEE on the decision-making process of aortic Toronto stentless prosthetic valve (TSPV) implantation. METHODS: Fifty-two consecutive patients undergoing elective AVR were collected prospectively. Multiplane TEE was performed before CPB to determine diameters of the aortic valve annulus and sinotubular junction. This was to evaluate the feasibility of TSPV implantation in the aortic position and to predict prosthesis size. Further TEE evaluation was carried out after CPB to assess prosthetic valve function. RESULTS: TEE allowed measurement of the aortic annulus and sinotubular junction, and enabled correct prediction of prosthesis size. Ultrasonic evaluation also revealed contraindications to TSPV implantation in five patients. In one case, color-Doppler examination led to immediate successful surgical correction of prosthetic incompetence. CONCLUSION: Intraoperative multiplane TEE examination is useful in the decision-making process in AVR with the TSPV by selecting patients suitable for the stentless valve, predicting prosthesis size, and checking prosthesis function.

Left ventricular remodeling after aortic valve replacement with the Toronto-SPV prosthesis.

The remarkable hemodynamic features of the aortic Toronto SPV prosthesis have been reported. To assess the efficacy of these characteristics to produce a favorable left ventricular remodeling and to test the limits of the dobutamine stress test to check these results, 25 consecutive patients, who had undergone aortic valve replacement with Toronto SPV, were monitored with dobutamine and exercise stress tests for 1 year. Among the prosthetic and left ventricular morphological and functional parameters evaluated, dobutamine infusion produced an overestimation of prosthetic and left ventricular outflow tract gradients, effective orifice area, and prosthetic resistance compared with the more physiological exercise test (P<.01). These misleading results were probably due to the inotropic and unloading effects of dobutamine in still hypertrophied hearts. Indexed myocardial mass and wall thickness decreased significantly during the follow-up period (P<.01), whereas left ventricular diastolic diameter and ejection fraction showed no significant variations. These data show that the positive left ventricular remodeling is due only to the regression of the hypertrophy and not to the reduction of left ventricular diameters. Based on results from this study, the dobutamine stress test should be avoided to evaluate patients with aortic valve prostheses and still present left ventricular hypertrophy. The Toronto SPV produces a favorable left ventricular remodeling during the first year of follow-up, and is likely to improve.

Artificial chordae in the treatment of anterior mitral leaflet pathology.

This report describes the authors' clinical experience with expanded polytetrafluorethylene (e-PTFE) sutures to replace the anterior mitral leaflet chordae for valve repair. Between November 1986 and July 1995, 203 patients underwent operations with e-PTFE chordae insertion. Among these, 122 had artificial chordae utilized for anterior mitral leaflet repair. Four patients had the valve replaced during the same operation because of an unsatisfactory result. One patient died from respiratory insufficiency 16 days after operation. Transoesophageal echocardiography at discharge from hospital showed no evidence of regurgitation in 81 cases, and trivial regurgitation in 36. During a mean follow-up of 36.6 (range 1-106) months two other patients died from causes unrelated to the valve repair, while one patient had a transient ischaemic attack returning to sinus rhythm. Two patients were reoperated on 12 and 18 months respectively after their initial operation for progression of valvular degeneration causing natural chordae rupture. Among the remaining 113 patients, 111 are in New York Heart Association functional class I and yearly transoesophageal echocardiography has shown absent or trivial regurgitation. The utilization of e-PTFE as artificial chordae for anterior mitral leaflet pathology is a safe and reliable procedure, yielding excellent results and increasing the number of candidates for valve repair.

Seven-year experience with chordal replacement with expanded polytetrafluoroethylene in floppy mitral valve.

Among 106 patients operated on for implantation of artificial mitral chordae (expanded polytetrafluoroethylene), usually associated with other traditional procedures, 82 had degenerative valve disease. Two of them had the valve replaced during the same operation because of residual regurgitation, and one patient died (1.3%) of respiratory insufficiency. Seventy-nine patients left the hospital and were followed up to 84 months. No late deaths and only one valve-related complication were reported. This occurred in a patient who required reoperation after 18 months for sudden recurrence of mitral regurgitation caused by the rupture of natural chordae, which had been shortened during the first procedure, whereas the artificial chordae had retained their function. The clinical experience confirms positive experimental data, because this technique was reliable with lasting results. Application of artificial chordae, associated with other traditional techniques, is useful to improve the results and to extend the indications for mitral valve repair.

Surgical technique for artificial mitral chordae implantation.

Failure of reconstructive procedures of the mitral valve is often ascribed to diffuse alteration of the subvalvular apparatus, which prevents the utilization of well-established techniques such as chordal transposition or shortening. For this reason, in 1986 after 2 years of animal experiments, we started the clinical use of expanded-polytetrafluoroethylene mitral chordae. Details of the surgical procedure are presented. Our experience is based on 51 patients with a mean follow-up of about 20 months (range 3-57). Four patients had the valve replaced during the same operation: one patient died later of cardiac failure and two underwent reoperation, 8 and 18 months after operation. Forty-one patients are in New York Heart Association Functional Class I and three in Class II. We suggest this technique in association with other traditional procedures to increase the number of mitral valves repaired, mostly because of degenerative etiology.

Artificial mitral valve chordae: experimental and clinical experience.

Failure of mitral valve reconstructive procedures often may be ascribed to severe or progressive alterations of subvalvar apparatus. Expanded polytetrafluoroethylene sutures were used to replace anterior leaflet mitral valve chordae in 8 animals (hypertensive dogs and growing sheep). After the positive results obtained during a 13-month follow-up, 5-0 sutures of the same material were introduced in clinical practice to replace mitral valve chordae. Twelve patients had two to six anterior leaflet chordae replaced for degenerative or rheumatic disease. In 3 patients, the intraoperative result was not acceptable and a prosthetic valve was inserted during the same operation. One case of late failure has been recorded so far (18 months after the procedure), owing to rupture of a natural chorda shortened at operation. Since that event, we have implanted supportive artificial chordae in case of diffuse alteration of natural chordae. The remaining patients show satisfactory hemodynamic results, and no valve-related events have been recognized up to 30 months after operation. We suggest use of 5-0 polytetrafluoroethylene sutures in replacing anterior leaflet chordae in degenerative, rheumatic, and congenital mitral valve diseases.

Efficacy and safety of predeposit blood autodonation in 500 cases of myocardial revascularization.

Since 1985 all patients scheduled for coronary artery bypass grafting have been evaluated for admission to a program of predeposited blood autodonation. From a total of 816 consecutive patients, 505 were admitted to the program (group 1). The other 311 (group 2) were excluded on the basis of one or more of the following criteria: 1) emergency surgical indication, 2) hemoglobin less than 12 g/dl, or 3) uncontrolled angina or clinically manifest cardiac failure. Postoperative use of homologous blood products was required by 16% of the group 1 and 44% of the group 2 patients (p less than 0.001). Altogether 597 patients (73%) had no contact with homologous blood products. There was no intergroup difference in the incidence of postoperative complications. Non-A, non-B hepatitis developed in three group 1 and four group 2 patients. Its incidence was 0.9% among all discharged patients and 3.2% of the homologous blood recipients. The findings emphasize the safety and value of the autodonation with predeposit program in significantly reducing the requirement for homologous blood in coronary artery bypass grafting.

Psychosocial outcome one year after heart surgery. A prospective study.

Ninety-nine of 118 patients receiving cardiac valve replacements (n = 55) or coronary artery bypass grafts (n = 44) were studied before surgery and again one year after surgery. Psychological, social, and physical variables were assessed. For the 19 subjects not returning for follow-up, medical data collected by their general practitioner were available. The physical results of surgery were good, with over 90% of the patients showing improvement. Mean scores for psychological distress and quality of life improved; however, a bad psychosocial adjustment was present in about 25% of patients at follow-up. Bad psychosocial adjustment was not correlated with surgical results. The preoperative variables most predictive of poor psychosocial outcome were high scores in the general hypochondriasis and irritability subscales of the illness Behaviour Questionnaire, bad psychological adjustment characterized by high anxiety, depression, and global scores on the Symptom Distress Checklist, and ischemic rather than valvular heart disease.