Peter Tesar

Allograft aortic valve replacement: long-term follow-up.

Aortic valve replacement using an allograft aortic valve has been performed on 804 patients. From December 1969 to May 1975, 124 patients received a nonviable allograft valve sterilized by incubation with low-dose antibiotics and stored for weeks by refrigeration at 4 degrees C (series 1). From June 1975 to January 1994, 680 patients received viable allograft valves, now cryopreserved early within 2 hours of collection from transplant recipient donors, 6 hours for multiorgan donor valves and 23 hours (mean) for autopsy valves from donor death. The 30-day mortality was 8.9% +/- 5% (95% confidence limits) for series I and 2.8% +/- 1% (95% confidence limits) for series II. Actuarial patient survival including hospital mortality at 15 years was 56% +/- 5% for series I and 62% +/- 5% for series II. The probability of a thromboembolic event was low, freedom at 15 years being 95% +/- 1% for patients receiving allografts with or without associated coronary bypass procedures and 81% +/- 5% for patients having allografts with other associated procedures (eg, mitral valve operations). Actuarial freedom from endocarditis was similar for the two series, 91% +/- 3% (series I) and 94% +/- 2% (series II) at 15 years. The freedom from valve incompetence, from reoperation for all causes, and from structural deterioration demonstrated clearly the inferiority of the 4 degrees C stored allograft valves. For structural deterioration as identified clinically, at reoperation and at death, freedom from this event at 15 years was 45% +/- 6% for series I and 80% +/- 5% for series II (p value for the difference is 0).(ABSTRACT TRUNCATED AT 250 WORDS)

Effect of preoperative supplementation with α-tocopherol and ascorbic acid on myocardial injury in patients undergoing cardiac operations

Augmentation of antioxidant defenses may help protect tissues against ischemia-reperfusion injury associated with operations involving cardiopulmonary bypass. In this study we examined the effect of pretreating patients with alpha-tocopherol (vitamin E) and ascorbic acid (vitamin C) or placebo on injury to the myocardium. Seventy-six subjects undergoing elective coronary artery bypass grafting participated in a prospective, double-blind, placebo-controlled randomized trial, receiving either placebo or both 750 IU dl-alpha-tocopherol per day for 7 to 10 days and 1 gm ascorbic acid 12 hours before the operation. Plasma alpha-tocopherol concentrations, raised fourfold by supplementation, fell by 70% after the operation in the supplemented group and to negligible levels in the placebo group. There were no significant differences between the groups with respect to release of creatine kinase MB isoenzyme over 72 hours, nor in the reduction of the myocardial perfusion defect determined by thallium 201 uptake. Electrocardiography provided no evidence of a benefit from antioxidant supplementation. Thus the supplementation regimen prevented the depletion of the primary lipid soluble antioxidant in plasma, but provided no measurable reduction in myocardial injury after the operation.

The initial experience with the ATS Medical mechanical cardiac valve prosthesis.

BACKGROUND From May 1994 through October 2000, a total of 1,146 patients underwent valve replacement with the ATS Medical mechanical cardiac valve prosthesis under a study protocol approved by international ethics committees (non-United States participants) or under a United States Food and Drug Administration-approved Investigational Device Exemption study. The study took place at 19 domestic and three international centers. METHODS As required by the Food and Drug Administrations Heart Valve Guidance Document, only isolated implants were included in the study (double-valve implants were excluded), with operative and follow-up data collected from each center. RESULTS Aortic valve replacement (AVR) was conducted in 801 patients (309 with coronary bypass) and mitral valve replacement (MVR) in 345 patients (78 with coronary bypass). Overall operative (< or = 30 days post implant) mortality was 2.1% (17 AVR = 2.1%, 7 MVR = 2.0%), 7 of which (AVR = 4, MVR = 3) were valve related. In 2,086 patient-years (1,459 AVR patient-years, 627 MVR patient-years) of follow-up, there were an additional 50 patient deaths of these, 18 were valve related, 9 due to anticoagulant related bleeding, 5 sudden/unexplained, and 1 each after stroke, thrombosis, prosthetic valve endocarditis, and thromboembolism. Late (>30 days post implant) valve-related complications included: transient and chronic thromboembolism (27 AVR (linearized rate 1.85%/patient-year) and 20 MVR (3.19%/patient-year), of which 11/47 (0.53%/patient-year) had chronic deficits, thrombosis (1 AVR = 0.07%/patient-year and 4 MVR = 0.64%/patient-year), paravalvular leak (10 AVR = 0.69%/patient-year and 8 MVR = 1.28%/patient-year), anticoagulant related hemorrhage (34 AVR = 2.33%/patient-year and 8 MVR = 1.28%/patient-year), prosthetic valve endocarditis (3 AVR = 0.21%/patient-year and 2 MVR = 0.32%/patient-year), and structural valve failure or dysfunction (0%). Echocardiographic gradients were proportional to valve size and did not significantly change over the follow-up period. CONCLUSIONS This study documented the ATS Medical mechanical cardiac valve prosthesis to be a valuable addition to the surgeons armamentarium in the treatment of cardiac valvular disease.

Protocol Guided Bleeding Management Improves Cardiac Surgery Patient Outcomes

Excessive bleeding is a risk associated with cardiac surgery. Treatment invariably requires transfusion of blood products; however, the transfusion itself may contribute to postoperative sequelae. Our objective was to analyse a quality initiative designed to provide an evidenced‐based approach to bleeding management.

Impact of optimising fluoroscopic implant angles on paravalvular regurgitation in transcatheter aortic valve replacements - utility of three-dimensional rotational angiography.

AIMS The clinical value of optimising implant angles during transcatheter aortic valve replacements (TAVR) remains undefined. The Aortic Valve Guide (AVG) is a proprietary software that provides structured analysis of three-dimensional images from rotational angiography (DynaCT). This study compares AVG with preprocedural multislice computed tomography (MSCT) and DynaCT in optimal implant angle prediction for TAVR, and evaluates if an optimised implant angle is associated with reduced paravalvular regurgitation (PVR). METHODS AND RESULTS One hundred and six consecutive patients were included, comprising three groups. Group 1 (n=19) underwent no preprocedural MSCT or DynaCT (or AVG); Group 2 (n=44) underwent periprocedural DynaCT, without AVG; Group 3 (n=43) had DynaCT with AVG. Implant angles yielded were graded as excellent, satisfactory or poor. Group 3 were more likely than Groups 2 and 1 to have excellent implant angles (83.7% vs. 52.3% vs. 42.1%, respectively, p=0.001). In 100 patients who had 30-day transthoracic echocardiogram follow-up, an excellent implant angle was significantly more likely to be associated with no PVR than a non-excellent angle (41.3% vs. 21.6%, respectively, p=0.045), independent of operator experience and THV used. CONCLUSIONS Optimising implant angles may be important in reducing PVR. This is significantly more likely to be achieved with AVG rotational angiography.

Determinants of in-hospital and long-term surgical outcomes after repair of postinfarction ventricular septal rupture

OBJECTIVES Surgical repair of post-myocardial infarction ventricular septal rupture is challenging with reported early mortality being substantial. In addition, congestive cardiac failure and ventricular tachyarrhythmia frequently occur long term after the operation, although frequency and predictive factors of these events have been poorly identified. METHODS A consecutive series of 68 patients who underwent repair of postinfarction ventricular septal rupture by 14 surgeons between 1988 and 2007 was studied. Fifty-eight (85%) patients underwent repair in an urgent setting (<48 hours after diagnosis). Coronary artery bypass grafting was concomitantly performed in 48 (71%) patients. Mean follow-up period was 9.2 +/- 4.9 years. RESULTS Thirty-day mortality was 35%, with previous myocardial infarction, previous cardiac surgery, preoperative left ventricular ejection fraction less than 40%, and urgent surgery being independent risk factors. Actuarial survival of 30-day survivors was 88% at 5 years, 73% at 10 years, and 51% at 15 years. Actuarial freedom from congestive cardiac failure and ventricular tachyarrhythmia was 70% and 85% at 5 years, 54% and 71% at 10 years, and 28% and 61% at 15 years, respectively. Independent predictors for congestive cardiac failure included hypertension, posterior septal rupture, residual interventricular communication, and preoperative left ventricular ejection fraction less than 40%, whereas concomitant ventricular aneurysmectomy and preoperative occlusion of the left anterior descending artery were independent predictors of ventricular tachyarrhythmia. CONCLUSIONS Long-term outcomes after surgical repair of postinfarction ventricular septal rupture was favorable, despite infrequent exposure by individual surgeons to the pathologic features, indicating that an aggressive surgical approach is warranted. Predictors of congestive cardiac failure and ventricular arrhythmia long term varied.

Influence of timing of intraaortic balloon placement in cardiac surgical patients

OBJECTIVE The study objective was to evaluate the association between timing of intraaortic balloon pump insertion and outcomes in patients undergoing cardiac surgery. METHODS All patients aged 18 years or more who underwent coronary artery bypass surgery, cardiac valve surgery, or thoracic aortic surgery between January 2002 and December 2007 were included. Data were obtained from cardiac surgery and intensive care databases. Patients were categorized as receiving a preoperative, intraoperative, or postoperative intraaortic balloon pump and compared with a reference group who did not receive an intraaortic balloon pump. Summary and descriptive statistics were used to compare the groups. Logistic regression was used to model in-hospital mortality, and survival methods were used to model time to event data, such as length of stay. RESULTS There were 7440 patients included over a 6-year period, of whom 217 (2.9%) received a preoperative intraaortic balloon pump, 184 (2.4%) received an intraoperative intraaortic balloon pump, and 42 (0.56%) received a postoperative intraaortic balloon pump. Logistic European System for Cardiac Operative Risk Evaluation-derived predicted risk of death was higher across all intraaortic balloon pump groups compared with the group with no intraaortic balloon pump. Observed in-hospital mortality was significantly lower in the preoperative group (10%) and the group with no intraaortic balloon pump (0.8%) compared with the intraoperative (16%) and postoperative (29%) groups. Risk-adjusted mortality was also lower in the preoperative group. CONCLUSION This study comparing outcomes in patients undergoing cardiac surgical procedures with timing of intraaortic balloon pump placement revealed that the use of preoperative intraaortic balloon pumps was associated with a strong trend toward reduction in in-hospital mortality despite a higher predicted mortality in this group. The study provides support to the growing body of literature advocating preoperative use of intraaortic balloon pumps in carefully selected patients.

Early experience of transaortic TAVI--the future of surgical TAVI?

BACKGROUND Trans-catheter aortic valve implantation (TAVI) is now a well recognised procedure for the high risk surgical patient with native or bioprosthetic aortic valve stenosis. Transfemoral and transapical implantation techniques are well described. With increasing referral of more marginal transapical patients, we describe our experience of a transaortic TAVI approach which we believe reduces the postoperative wound pain, respiratory complications, operative risk and hospital stay. METHODS Patients referred for surgical TAVI underwent trans-catheter aortic valve implantation via an upper sternotomy and direct cannulation of the ascending aorta. RESULTS Thirteen patients with a mean age of 81 years underwent transaortic Edwards SAPIEN valve implantation. There was no in hospital mortality in our series. One patient required insertion of a permanent pacemaker for complete heart block. There were no aortic cannulation complications. CONCLUSION The transaortic TAVI approach provides good exposure of the distal ascending aorta, a familiar cannulation site for cardiac surgeons. Our initial experience demonstrates the approach to be a safe technique with the potential for faster and less complicated recovery in patients undergoing surgical TAVI procedures. With further experience and greater acceptance, the transaortic approach may ultimately become the procedure of choice for patients unsuitable for a transfemoral approach.

Cryopreserved viable allograft aortic valves

The clinical experience of allograft aortic valve replacement (AVR) began at the Prince Charles Hospital in 1969. From the commencement of this experience until May 1975, the method of valve sterilisation was antibiotic exposure, and the valves were stored in nutrient medium at 4 °C for periods up to several weeks before implantation. There is considerable evidence from this and other clinical experience (1, 6, 15, 16), as well as from experimental evidence (9, 10), that this process produces a non-viable valve, incapable of self-repair. Its clinical performance is characterised by an unacceptable incidence of late cusp rupture, reflecting leaflet degeneration (5). At the same time, experimental work was progressing at the Prince Charles Hospital (17), as well as at other centres (2, 8, 11, 12) in an endeavour to develop a method of storing valves indefinitely with maintenance of leaflet cell viability. This direction was taken as a result of work by Angeli (3, 12) indicating the importance of leaflet viability as a determinant of long-term valve durability. At the Prince Charles Hospital the use of antibiotic sterilised 4 °C refrigerated valves was discontinued in June 1975, and an era of cryopreservation of allograft aortic valves commenced. A description of the cryopreservation methods have been detailed elsewhere (14, 15), but in essence it involves “sterile” procurement, low-dose antibiotic exposure for 24 h and cryopreservation in the vapour phase of liquid nitrogen (approx. - 180 °C to - 190 °C) with the valve packaged and immersed in the cryoprotectant 10% dimethyl sulphoxide.

The silent and apparent neurological injury in transcatheter aortic valve implantation study (SANITY): concept, design and rationale.

BackgroundThe incidence of clinically apparent stroke in transcatheter aortic valve implantation (TAVI) exceeds that of any other procedure performed by interventional cardiologists and, in the index admission, occurs more than twice as frequently with TAVI than with surgical aortic valve replacement (SAVR). However, this represents only a small component of the vast burden of neurological injury that occurs during TAVI, with recent evidence suggesting that many strokes are clinically silent or only subtly apparent. Additionally, insult may manifest as slight neurocognitive dysfunction rather than overt neurological deficits. Characterisation of the incidence and underlying aetiology of these neurological events may lead to identification of currently unrecognised neuroprotective strategies.MethodsThe Silent and Apparent Neurological Injury in TAVI (SANITY) Study is a prospective, multicentre, observational study comparing the incidence of neurological injury after TAVI versus SAVR. It introduces an intensive, standardised, formal neurologic and neurocognitive disease assessment for all aortic valve recipients, regardless of intervention (SAVR, TAVI), valve-type (bioprosthetic, Edwards SAPIEN-XT) or access route (sternotomy, transfemoral, transapical or transaortic). Comprehensive monitoring of neurological insult will also be recorded to more fully define and compare the neurological burden of the procedures and identify targets for harm minimisation strategies.DiscussionThe SANITY study undertakes the most rigorous assessment of neurological injury reported in the literature to date. It attempts to accurately characterise the insult and sustained injury associated with both TAVI and SAVR in an attempt to advance understanding of this complication and associations thus allowing for improved patient selection and procedural modification.