Redo isolated tricuspid valve surgery: prediction of in-hospital mortality using the TRI-SCORE

Background

Redo isolated tricuspid valve surgery (ITVS) is rarely performed. The TRI-SCORE reliably predicts in-hospital mortality after ITVS on native valve but has not been tested in the setting of redo interventions.

Purpose

We aimed to compare the predictive value of the TRI-SCORE to other surgical risk scores for redo ITVS.

Methods

Using a mandatory administrative database, we identified all consecutive adult patients who underwent a redo ITVS at 12 French tertiary centers between 2007 and 2017. Baseline characteristics and outcomes were collected from chart review and the TRI-SCORE, Logistic EuroSCORE, EuroSCORE II and STS were calculated.

Results

We identified 70 patients who underwent a redo ITVS (mean age 54±15 years, 63% female). Prior intervention was a repair in 51% and a replacement in 49%. A tricuspid valve replacement was performed in all patients. In-hospital mortality was 10%. The TRI-SCORE was the only risk score associated with in-hospital mortality (p=0.01). Area under the receiver operating characteristic curve for the TRI-SCORE was 0.83, much higher than with logistic EuroSCORE (0.58), EuroSCORE II (0.61) or STS (0.59). The table presents the observed and predicted values of in-hospital mortality according to TRI-SCORE categories.

Conclusion

The TRI-SCORE accurately predicted in-hospital mortality after redo isolated tricuspid valve surgery and may guide the clinical decision-making process especially as transcatheter therapies are emerging.

Funding Acknowledgement

Type of funding sources: None.

Cyclosporine-related posterior reversible encephalopathy syndrome after heart transplantation: should we withdraw or reduce cyclosporine?: case reports

Cyclosporine (CsA) related encephalopathy has not been well documented after heart transplantation. We report 2 cases of posterior reversible encephalopathy syndrome (PRES). The first case was a 68-year-old woman who underwent heart transplantation and received immunosuppression with mycophenolate mofetil, prednisone, and CsA. On day 14, she developed arterial hypertension, headache, visual disturbances, and generalized seizures. Fluid-attenuated inversion recovery magnetic resonance imaging (MRI) of the brain showed diffuse and bilateral high signals in the frontal posterior and the occipital areas. The second case was a 19-year-old man with a heart transplant receiving immunosuppression with prednisone and CsA. On day 44, he developed acute headache and generalized seizures. T2-weighted MRI of the brain showed diffuse high signals in the cerebellum, right lenticular and occipital areas. In both cases blood CsA concentration was therapeutic. Both cases recovered but in the first case neurologic findings were reversed only after CsA withdrawal.

[Whipple's disease endocarditis: report of 5 cases and review of the literature]

PURPOSE

Endocarditic lesions (infectious endocarditis) associated with Whipple's disease are exceptional. We report five cases from the cardiovascular and pneumologic hospital Louis Pradel in Lyon.

METHOD

We have collected all cases of Tropheryma whipplei endocarditis diagnosed between 1995 and 2004.

RESULTS

Five men with a mean age of 53 years at time of diagnosis. The symptoms were essentially cardiovascular: murmur, embolism in 3 cases, and heart failure secondary to valvular insufficiency in 2 cases. The valvular involvement, double in 3 cases, was more often aortic. Vegetations were present in all patients and valvular destruction sometimes very important. A low grade fever was present in 4 cases, associated with weight loss in 2 cases. The only extra-cardiac symptoms were arthralgias or arthritis in all cases, considered in 3 patients as seronegative rheumatoid arthritis, B27+ spondylarthritis, and psoriasic arthritis. Their was no other clinical manifestations of Whipple's disease, particularly digestive, ocular, neurologic or adenopathy, and duodenal biopsies secondarily performed in 4 cases were non contributive. This differs from literature as an extra-cardiac location was identified in 11 out of 17 cases. The diagnosis was obtained by histology and PCR on the cardiac valves, as all the patients underwent surgery. The evolution was favourable with a prolonged antibiotic therapy.

CONCLUSIONS

These report confirms the existence of endocarditic forms of the Whipple's disease, in which the single extra-cardiac manifestation is rheumatologic, and reminds us the usefulness of histology and PCR on the cardiac valves at the time of valvular surgery.

[Replacement of the ascending aorta with conservation of the aortic valve. Results of 50 cases using the Tirone David procedure]

Aortic valve sparing operations are now widely accepted for ascending aortic aneurysm surgery. We herein report our experience of the Tirone David procedure in larger indications. From January 1997 to August 2003, 50 Tirone David procedure have been performed on 36 male and 14 female (mean age: 60 +/- 15). Five patients presented a Marfan disease and 4 acute dissections. Grade III or IV aortic insufficiency was frequent (40%). Aortic diameter was not particularly dilated, ranging from 44 to 78 mm (mean: 57 +/- 10 mm). Mean ejection fraction: 57 +/- 10%. Mean left ventricular end diastolic diameter =63 +/- 7 mm. An associated mitral valve repair and 1 coronary bypass were necessary. Mean cross clamp and bypass times =94 min and 122 +/- 28 min respectively. There was one in-hospital mortality. Secondary mortality affected 2 patients (non-cardiac deaths), for a cumulative follow-up of 946 months. During follow-up continence control was always excellent, only 1 bicuspid valve had an aortic insufficiency >grade II. Tirone David procedure gave satisfactory results as regards both aortic ectasia and aortic regurgitation control. We consider it feasible even in case of aortic dissection but caution is required when facing bicuspid aortic valves.

Alteration of the left ventricular contractile reserve in heart transplant patients: a dobutamine stress strain rate imaging study

BACKGROUND

Strain rate imaging (SRI), a recently developed Doppler-derived process, allows quantification of myocardial systolic function. We investigate whether SRI quantifies the contractile reserve during dobutamine stress tests in heart transplant patients (HT), when compared with normal individuals.

METHODS

An incremental dobutamine test (5 to 40 microg/kg per minute) was performed in 10 HT and 15 control subjects, all of whom displayed normal coronary angiography. Gray-scale and color myocardial Doppler data were acquired in standard B-mode views at baseline, low-dose, peak, and recovery. Longitudinal SR was processed from the myocardial velocities for each segment. The changes in maximal systolic SR were used to quantify myocardial contractile reserve.

RESULTS

Dobutamine infusion failed to induce clinical symptoms or electrocardiographic (ECG) changes in either group. Visually determined wall motion score was considered normal in all segments for each stage of the dobutamine stress. Heart rate was augmented similarly in both groups during dobutamine infusion. In controls, systolic SR increased gradually with incremental dobutamine dose and returned to baseline values upon recovery. Conversely, in HT patients, the increase in systolic SR was blunted at peak dobutamine, at which point it was significantly different vs controls.

CONCLUSIONS

Quantitative assessment of myocardial function using SRI during dobutamine stress revealed an impaired contractile reserve in HT patients with normal coronary angiography. These subtle changes in regional myocardial function could not be identified using visual wall motion scoring. Additional studies are necessary to evaluate whether SR imaging detection of contractile reserve impairment will improve clinical efficiency or event prediction in this population.

Acute rejection and cardiac graft vasculopathy in the absence of donor-derived ICAM-1 or P-selectin

BACKGROUND

ICAM-1 and P-selectin are molecules that facilitate adhesion of circulating leukocytes to vessel walls. We have investigated the role of donor-derived ICAM-1 and P-selectin in acute and chronic cardiac allograft rejection.

METHODS

C57BL/6J (H-2(b)) mice were used as donors for heterotopic heart transplantation into CBA/Ca (H-2(k)) recipients. The donors were wild-type or homozygous for gene mutations of ICAM-1 or P-selectin. We measured acute rejection in non-immunosuppressed recipients by daily palpation and sacrificed mice at Days 2, 4, and 6 for immunohistochemical analysis. For chronic rejection, recipients received monoclonal antibody against CD4+ T cells. We removed hearts at Days 60 to 62 for histologic assessment of vasculopathy using quantitative morphometry to measure intimal thickening.

RESULTS

Time (days) to rejection was 7.1 +/- 0.57 for wild-type (n = 10), 7.0 +/- 0.71 for ICAM-1 -/- (not significantly different, n = 7) and 6.1 +/- 0.33 (p = 0.001) for P-selectin -/- donors. ICAM-1 deficiency was associated with delayed infiltrate at Day 4 compared with wild-type. In the model of chronic rejection, elastin-positive vessels showed a mean occlusion of 34% +/- 3% in transplanted wild-type hearts; vessels were divided into those showing 0% to 20%, 20% to 50%, and 50% to 100% occlusion. We observed no difference in the number of affected vessels or the amount of vascular thickening in donors lacking ICAM-1 or P-selectin compared with wild-type controls.

CONCLUSIONS

The absence of ICAM-1 or P-selectin in donor tissues neither lengthens the time of allograft survival nor inhibits the vascular lesions associated with chronic rejection. Indeed, the absence of P-selectin may exacerbate alloimmune injury.

Thiopurine S-methyltransferase gene polymorphism is predictive of azathioprine-induced myelosuppression in heart transplant recipients

Azathioprine (AZA) is metabolized via the cytosolic enzyme thiopurine S-methyltransferase (TPMT). TPMT activity exhibits genetic polymorphism with four prevalent (75%) mutant alleles TPMT*2 (G238C) and TPMT*3 (A719G and/or G460A) and a wild-type allele TPMT*1. To test the hypothesis that presence of these mutations is associated with greater toxicity of AZA in heart transplant recipients, 30 consecutive patients treated with AZA were followed up for the first month after heart transplant. Mutation of TPMT gene (mutation-specific polymerase chain reaction-based methods) was observed in four patients (A719G: n = 2; A719G plus G460: n = 2). Agranulocytosis did not occur in patients with the wild genotype. It occurred in the two patients with mutation A719G and there was a 40% drop in neutrophils in the two other patients. Discontinuation of AZA in the four mutant patients corrected for the drop. Presence of TPMT mutations is associated with a greater likelihood of agranulocytosis. Determination of these mutations could reduce the risk for hematological side-effects.

Kinetic characterization of CMD-A2-Gd-DOTA as an intravascular contrast agent for myocardial perfusion measurement with MRI

Recent developments in magnetic resonance imaging (MRI) using specific contrast media allow the assessment of myocardial perfusion. The purpose of this study was to characterize the intravascular properties of a new macromolecular contrast agent, CMD-A2-Gd-DOTA, to evaluate myocardial perfusion. Two groups of isolated pig hearts perfused at various controlled flows were used. To demonstrate the intravascular properties of CMD-A2-Gd-DOTA, the agent was simultaneously injected with 99mTc-labeled red blood cells in five hearts (group 1). Tracer kinetics of both compounds were assessed by coronary sinus effluent sampling, radioactivity counting and concentration determination in samples for first-pass time curves measurements. Five other hearts (group 2) were studied using a two-slice turboFLASH sequence on a 1.5-T whole-body MRI in order to evaluate first-pass CMD-A2-Gd-DOTA signal intensity (SI) versus time curves. In group 1, for the studied flows ranging from 0.8 to 3.1 ml/min(-1) x g(-1), CMD-A2-Gd-DOTA showed first-pass concentration curves typical of an intravascular contrast agent. In group 2, MRI parameters, i.e., upslope and mean transit time of SI time curves correlated strongly with myocardial perfusion. Within the physiologic range of flows, CMD-A2-Gd-DOTA was able to demonstrate tracer kinetics for in vivo assessment of myocardial perfusion using MRI.

[Ten-year experience with heart transplantation (1987-1997)]

OBJECTIVES

Analyze ten years experience with heart transplantation at the Dijon University Hospital and determine which parameters control mid and long term outcome.

PATIENTS AND METHODS

One hundred thirty six heart transplantations were performed over a 10 year period (1987-1997) in 118 men and 18 women aged 51-87 years. Heart transplantation was indicated on the basis of the following criteria: ejection fraction *20%, pulmonary arteriole resistance < 6 Wood units, peak oxygen uptake < 14 l/kg/min. The Shumway or anatomic technique was used. The triple immunosuppressive protocol combined corticosteroids, azathioprine and cyclosporin. The same team conducted the post-transplantation follow-up with regular programmed consultations in addition to those requested by the general practitioner, the cardiologist or the patient. Follow-up was oriented according to the clinical situation (blood chemistry, cell counts, cyclosporinemia, search for infection, echocardiography, endomyocardial biopsy, coronarography).

RESULTS

Five patients (3.6%) died when still on the waiting list. Absolute emergency transplantation was performed for patients (28.1%) including 8 (5.9%) after circulatory assist. Hospital mortality was 11.7% and late mortality was 16.1%. Actuarial survival was 78% at 1 year, 71% at 5 years and 69% at 10 years. Among the survivors, 94% were taking two, three or even four drugs for hypertension. Cyclosporin levels decreased and creatinine levels increased. Episodes of rejection were minimal: 86.57% of the biopsies were * grade 1 and 4.45% * grade 2. Cytomegalovirus infection was documented and treated in 7.55% of the cases. Incidence of graft coronary artery disease was 3.4% at 1 year, 6.5% at 2 years and 7.9% at 3 years.

CONCLUSION

Our follow-up structure where the same small team conducts regular examinations together with our approach to heart transplantation appears to be the main factor leading to the quality results obtained in this series.

Thoracoscopic epicardial radiofrequency ablation for vagal atrial fibrillation in dogs

Epicardial radiofrequency catheter ablation of the atria in the open-chest dog has been shown to reduce inducibility of atrial fibrillation. Video-assisted endoscopic techniques decrease the operative trauma in adult thoracic surgery. We report our results of video-assisted thoracoscopic radiofrequency catheter ablation of the atria for the prevention of atrial fibrillation induction in canines. In 12 consecutive anesthetized dogs, induction of sustained atrial fibrillation was reproducibly obtained by burst pacing and cervical vagal stimulation. In six dogs, biatrial ablation was performed through right and left minithoracotomies and guided by video-assisted endoscopic techniques. The remaining six dogs underwent a video-guided left atrial procedure. Long continuous and transmural lesions were produced using epicardial temperature controlled radiofrequency energy delivery according to a simplified maze approach. Transmural lesions were demonstrated at the end of the study by examination of the heart. Sustained atrial fibrillation was still inducible after the right atrial ablation but sustained atrial fibrillation could not be induced following left atrial ablation. In acute canine studies: (1) epicardial radiofrequency catheter ablation of the atria is feasible using video-assisted endoscopic techniques; (2) ablation extended or confined to the left atrium appears to be effective in preventing the inducibility of sustained vagal atrial fibrillation; and (3) ablation of the right atrium alone had no antiarrhythmic effect.

Influence of temperature on tracheal tube cuff pressure during cardiac surgery

BACKGROUND

Lateral wall pressure may cause tracheal injury by affecting tracheal capillary blood flow. Damage to the trachea is less severe when lateral wall pressure exerted by the endotracheal tube cuff does not exceed the mean capillary perfusion pressure of the mucosa. The purpose of this study was to determine the effects of hypothermic and normothermic cardiopulmonary bypass (CPB) on tracheal tube cuff pressure dynamics.

METHODS

Twenty-two patients were studied during normothermic CPB (pulmonary artery blood temperature in the CPB period between 36 and 35 degrees C), and 22 patients during hypothermic CPB (pulmonary artery temperature in the CPB period between 32 and 28 degrees C). A Mallinckrodt Medical Lo-Contour Murphy tracheal tube, with high-volume, low-pressure cuff was used without lubricant. Intracuff pressure (ITCP) was recorded at end-expiration before, during and after cardiopulmonary bypass.

RESULTS

ITCP measurements were different between groups during CPB at aortic cross-clamping (13.9 +/- 0.8 mmHg in the normothermic group versus 11.3 +/- 0.4 mmHg in the hypothermic group, P < 0.05), and respectively during CPB after aortic declamping (15.3 +/- 0.8 mmHg and 12.6 +/- 0.8 mmHg, P < 0.05) and after CPB at the end of surgery (16.8 +/- 0.7 mmHg and 18.6 +/- 0.3 mmHg, P < 0.05).

CONCLUSION

We conclude that the ITCP is higher in normothermic CPB than in hypothermic CPB; however, the clinical significance of this observation needs further investigation.

[Infections secondary to implantation of cardiac pacemakers]

Infectious complications of pacemaker implantation are not common but may be particularly severe. Localised wound infections at the site of implantation have been reported in 0.5% of cases in the most recent series with an average of about 2%. The incidence of septicaemia and infectious endocarditis is lower, about 0.5% of cases. The operator's experience, the duration of the procedure and repeat procedures are considered to be predisposing factors. The main cause of these infections is though to be local contamination during the implantation. The commonest causal organism is the staphylococcus (75 to 92%), the staphylococcus aureus being the cause of acute infections whereas the staphylococcus epidermis is associated with cases of secondary infection. The usual clinical presentation is infection at the site of the pacemaker but other forms such as abscess, endocarditis, rejection of the implanted material, septic emboli and septic phlebitis have been described. The diagnosis is confirmed by local and systemic biological investigations and by echocardiography (especially transoesophageal echocardiography) in cases of right heart endocarditis. There are two axes of treatment: bactericidal double antibiotherapy and surgical ablation of the infected material either percutaneously or by cardiotomy. Though controversial, and unsupported by scientific evidence, the role of systematic, preoperative, prophylactic antibiotic therapy in the prevention of these complications seems to be increasing.

[Reversible graft dysfunction after cardiac transplantation]

The authors report 3 cases of major graft dysfunction after cardiac transplantation which recovered completely with biventricular mechanical assistance in 4 to 8 days. All three cases were primary biventricular graft failures in patients with normal preoperative pulmonary resistances. These early dysfunctions (with no signs of myocardial infarction on electro- or echocardiography and in the absence of abnormal increased peri-operative enzyme levels) associated with total functional recovery conforming to the definition of the phenomenon of myocardial stunning. These results argue in favour of aggressive management of primary graft dysfunction.

[Thoracic aortic aneurysm in Marfan syndrome]

Thoracic aortic aneurysms are the main cardiovascular complication of Marfan's syndrome. Elastic tissue dystrophy of the ascending aorta is responsible for appearances of cystic medial necrosis in the major forms. Dilatation of the ascending aorta is progressive with time. The risk of dissection and rupture, an acute complication of Marfan's syndrome, is very high when the aortic dilatation reaches 60 mm, although dissection may be observed with dilatation of 50 mm. Aortic regurgitation is found in half the cases. Echocardiography, CT scan and MRI provide accurate assessment of the anatomy of the lesions and help in following up the dilatation. Betablocker therapy slows down the progression of the dilatation. Bentall's procedure was first described in 1968 with its technical variants for reimplantation of the coronary arteries: Cabrol's procedure, technique of periostal lean-to, the button technique, are major advances in the surgical treatment of ascending aortic aneurysms. The life expectancy is reported to be about 90% at 5 years and 75 to 80% at 10 years. Reoperation is sometimes necessary because of pseudo-aneurysms occurring as a late complication at the operation site or because of other aneurysms developing. Progress in the field of genetics is a hope for the future.

Mitral subvalvular apparatus: different functions of primary and secondary chordae

BACKGROUND

The aim of this study was to compare the function of the primary chordae attached to the free edge with that of the secondary chordae attached to the ventricular surface of the anterior mitral leaflet.

METHODS AND RESULTS

An isolated working pig heart model was used. Three groups of 7 hearts were compared: Group A was the control group with intact leaflets. In group B, the primary chordae of the anterior leaflet were sectioned and the secondary chordae were left intact before assembly of the working heart model. In group C, the secondary chordae were sectioned and the primary chordae left intact. In group B, atrial and ventricular pressure evidenced dramatic mitral regurgitation. Video monitoring showed significant prolapse of the free edge of the anterior leaflet. Acute mitral regurgitation accounted for the decrease in aortic flow rate to 30 mL/min, significantly lower than in the control group (P=.006). In group C, sectioning of the secondary chordae left a competent mitral valve together with good coaptation of the anterior and posterior leaflets shown by video monitoring. However, aortic flow was lower than in the control group (P=.007), and ultrasonomicrometry evidenced impaired function (P=.009).

CONCLUSIONS

This study suggests that the primary and secondary chordae of the mitral subvalvular apparatus have different functions. The primary chordae of the anterior leaflet appeared to be more involved in mitral valve competence, whereas the secondary chordae appeared to be more involved in left ventricular geometry and function.

Design of an isolated pig heart preparation for positron emission tomography and magnetic resonance imaging

RATIONALE AND OBJECTIVES

Validation of new positron emission tomography (PET) tracers or magnetic (MR) imaging contrast agents is based on isolated rodent heart preparations. The use of larger animals could provide a more direct validation using the devices used for humans.

METHODS

An isolated pig heart preparation has been developed and adapted to the technical constraints of whole body PET and MR imaging. This preparation could be used either in the Langendorff or working mode after selective cannulation of both coronary arteries.

RESULTS

The authors showed that quantification of regional kinetics of PET tracers was possible using this preparation by measuring fluorine-18-labeled deoxyglycose (18FDG) kinetics in remote and ischemic territories. Experiments using MR imaging contrast agents, for myocardial perfusion, demonstrated the ability of this preparation to accurately validate these contrast agents over a wide range of flow rates.

CONCLUSIONS

An isolated pig heart preparation could be developed to fulfill the constraints of PET and MR imaging, and proved useful for the study of the distribution of different tracers or contrast media developed for functional cardiac imaging in humans.

Defibrillation threshold and electrode configurations: an experimental study testing three configurations in twelve pigs

OBJECTIVE

The choice between epicardial or subcutaneous patches remains unclear and depends essentially on the team's habits. This study tested how much an additional patch can decrease defibrillation threshold (DFT), and compared a Subcutaneous Array and an epicardial patch. Today most implantable automatic defibrillators have a transvenous endocardial configuration alone but when the DFT remains high an additional patch is necessary.

EXPERIMENTAL DESIGN

Three different configurations were tested with biphasic shocks in 12 pigs: Endovenous lead (Endo), Endovenous lead + subcutaneous patch (Endo + SQ) and Endovenous lead + epicardial patch (Endo + Epi). For each animal DFTs were determined in a balanced random order for the 3 configurations. Ventricular fibrillation was induced by pacing (30 Hz, 8 V, for 5 seconds). DFT was accurately measured with the up/down procedure until 3 reversal of defibrillation success or failure occurred. DFTs (mean +/- SD) were extracted and compared using paired t test and analysis of variance.

RESULTS

DFTs were 14.6 +/- 11.0 J for Endo and significantly decreased (p < 0.01) when an additional SQ (9.4 +/- 7.2 J) or epicardial patch (8.9 +/- 6.5 J) was added to endovenous lead, without significant difference between Endo + SC and Endo + Epi configurations.

CONCLUSIONS

Regarding this important decrease of DFT (respectively -35% for Endo + SC and -39% for Endo + Epi), additional patches should be more often recommended in patients with low safety margin of DFT. In those cases subcutaneous patches should be preferred instead of epicardial patches. Moreover, an additional reason to recommend this attitude could be the possible generator batteries saving.

Beneficial actions of preconditioning and stretch on postischemic contractile function of isolated working rat heart: effects of staurosporine

Preconditioning is commonly induced by a brief ischemic insult; myocardial stretch can trigger this protection by an unknown mechanism. Myocardial stretch preconditions the in vivo canine heart; however, the existence of a stretch-induced protection in the rat heart remains unknown. The purpose of this study was to test this myocardial protection induced, in isolated working rat heart, by global ischemia and stretch initiated by a transient increase in the left ventricle (LV). Isolated rat hearts underwent 30 min of global ischemia followed by 30 min of reperfusion. Before this, hearts received a 15-min period of either no intervention (control; C), 5 min of global ischemia + 10 min of reperfusion (preconditioning; PC) or 5 min of stretch + 10 min with no intervention (stretch; S). Stretch was induced by a transient increase in LV preload from 5 to 20 cm H2O. LV work started under a afterload of 80 cm H2O. Control, PC, and S hearts received either no drug (untreated) or staurosporine (50 nM), a protein kinase C inhibitor, before the "preconditioning" period. Creatine kinase (CK) release, ventricular fibrillation during reperfusion, and postischemic recovery of contractile function (aortic flow) were the end points of the study. In the S group, the abrupt increase in preload resulted in a significant increase of aortic flow (42 +/- 2 to 47 +/- 2 ml/min; p < 0.05). During the 30-min reperfusion period, control hearts displayed a poor recovery of contractile functions (8 +/- 3 ml/min, 30 min after reflow, versus 40 +/- 2 ml/min at baseline; p < 0.05). Both untreated PC and S groups exhibited a significant reduction in CK release, incidence of ventricular fibrillation (55% of control hearts developed persistent VF vs. 6% in both the PC and S groups), and postischemic dysfunction during reperfusion (p < 0.05 vs. control). Staurosporine prevented these beneficial effects in PC and S groups. Our study suggests that myocardial protection can be induced by stretch in the isolated working rat heart, likely through activation of protein kinase C. In conclusion, our results show that ischemic preconditioning and stretch had comparable favorable effect on functional recovery after a sustained ischemic insult in the isolated rat heart.

Outcome of atrial fibrillation after mitral valve repair

OBJECTIVE

The aim of the study was to evaluate the prognostic factors for return to sinus rhythm after mitral valve repair.

METHOD

One hundred ninety-one patients underwent surgery for mitral valve repair, including 142 procedures for valve repair only (74%). The patients with preoperative atrial fibrillation (50.5%) were older, clinically more symptomatic, and had a greater degree of left atrial dilation than the patients who had sinus rhythm.

RESULTS

Preoperative cardiac rhythm, the duration of preoperative atrial fibrillation, and a lesser degree of left atrial hypertrophy are significant prognostic factors independent of the maintenance of sinus rhythm. The probability of return to stable sinus rhythm was 93.7% when sinus rhythm was already present before the operation and 80% when atrial fibrillation was intermittent or of less than 1 year's duration; probability declined abruptly for durations over 1 year. No significant difference in patient survival was noted between those who had sinus rhythm (99% +/- 0.9% at 1 year and 86% +/- 6.6% at 5 years) and those who had atrial fibrillation in the preoperative period (95% +/- 3.1% at 1 year and 86% +/- 8.4% at 5 years). In contrast, the postoperative return to sinus rhythm was associated with 99% +/- 0.9% and 94% +/- 4.8% survivals at 1 and 4 years versus 97% +/- 1.5% and 77% +/- 13% in the event of postoperative atrial fibrillation.

CONCLUSION

The aim of restoring postoperative sinus rhythm after mitral valve repair should lead to surgery being conducted on patients who have sinus rhythm or recent-onset atrial fibrillation. Surgery for atrial fibrillation may be of value in patients with a long history of atrial fibrillation, providing that it does not induce prohibitive excess mortality.

Long-term follow-up of small (size 20 and 21) Medtronic-Hall aortic valve prostheses

BACKGROUND

Our goal was to study the long-term follow-up of patients having aortic valve replacement and to focus particularly on the patients receiving small prostheses.

METHODS

Four hundred twenty-eight Medtronic-Hall valves were implanted (156 size 20 or 21 mm, 149 size 22 or 23 mm, and 123 size 25 or 27 mm). Group 20-21 had a higher number of female patients, more associated coronary lesions, and more patients with aortic stenosis.

RESULTS

The actuarial survival rate at 8 years was 80% for group 20-21, 80% for group 22-23, and 76% for group 25-27 (p = not significant). In group 20-21, the actuarial event-free rates at 8 years were as follows: thromboembolic complications, 94%; prosthetic valve endocarditis, 99%; reoperation, 98%; and hemorrhagic complications, 78%. The only factors of prognostic value in this group were age and associated coronary lesions.

CONCLUSIONS

The durable nature of the results obtained with the Medtronic-Hall 20- and 21-mm prostheses compared with large-diameter prostheses allows the use of a simple and reliable surgical technique and should mean that indications for ring enlargement become rare.

Mechanical cardiac valve thrombosis in patients in critical hemodynamic compromise

BACKGROUND

Valve obstruction is a life threatening complication of mechanical valve prosthesis.

METHODS

From 1985 to 1993, 29 consecutive patients were hospitalized in our intensive care unit for mechanical prosthetic valve thrombosis (PVT). There were 12 men and 17 women aged 25-75 years (57 +/- 12). Prosthetic valve location was mitral in 14 patients, aortic in 6, aortic and mitral in 9. PVT occurred from 15 days to 174 months (67 +/- 52 months) after surgery. Delay from first symptoms to hospitalization ranged from 1 to 45 days (11 +/- 11).

RESULTS

First clinical symptoms were progressive left heart failure in 17 patients, stroke in 6, and chest pain in 6. Furthermore, acute myocardial infarction was later documented in 3. Left heart failure NYHA III-IV was present in 26 patients (90%) on admission and 10 of those were in cardiogenic shock. Anticoagulation regimen was inadequate in 13 cases (45%). It has been recently stopped in 8 patients and incorrectly conducted in 5. Total hospital mortality was 41.3% (12). It was independent of type and position of the valve prosthesis. Diagnosis of PVT was only made at autopsy in 3 patients who died of recurrent myocardial infarction (2) or cardiogenic shock (1). Five further patients died before any surgery could be attempted (cardiac arrest: 2, cardiogenic shock: 3). Valve replacement could be done in 21 cases, 7 of whom were in cardiogenic shock and 9 had severe pulmonary edema. Four patients died after surgery, the operative mortality was 19%.

CONCLUSION

PVT remains a serious complication of mechanical heart valve prostheses. Overall mortality rate is high, related to difficulty to diagnosis, delay to hospitalization and severe clinical condition at admission. In our study, operative risk remained acceptable even when the clinical presentation was severe.

Long conservation organs in heart transplantation: postoperative results and long-term follow-up in fourteen patients

Between 1988 and 1995, 14 heart transplantations were performed after a long preservation period (10 to 13 hours). The transplantation procedure (Shumway) was standard, and our results were achieved through the implementation of a very strict reperfusion technique that included low pressure and low cardiopulmonary bypass output for the first 10 minutes. Three patients died during the postoperative period, and the survival rate was 75% at 1 year and 71% at 5 years. The results obtained with hearts stored for such long periods are comparable to the results obtained with hearts stored for less than 4 hours.

Images in cardiology. A threatened paradoxical embolism

Images

Intracardiac air clearing in valvular surgery guided by transesophageal echocardiography

BACKGROUND AND AIMS OF THE STUDY

Air embolism during open heart surgery seems to be a common occurrence and may be responsible for neuropsychological deficit or myocardial damage.

MATERIAL AND METHODS

Forty-two consecutive patients undergoing valvular surgery were studied using the long axis view of the heart by two dimensional transesophageal echocardiography (TEE). The patients were randomized into two groups of 21 each. In group 1, the routine air evacuation method was used. In group 2, the same air evacuation method was used and controlled with a Doppler ultrasonic probe adjusted around the root of the aorta. At the end of air evacuation, intracardiac microbubbles and retained air were analyzed with TEE and when air was founded, its location was communicated to the surgeons who tried to remove it by shaking the heart and tilting the operating table for 15 minutes. The patients were assessed for detection of cardiac or neurological postoperative complications.

RESULTS

The incidences of microbubbles and retained air were 57% and 43% in group 1, and 62% and 38% in group 2 respectively (ns). The mean grade of microbubbles was lower in group 2: 1.4 +/- 0.8 vs. 2.2 +/- 0.9, p < 0.05. TEE allowed to significantly decrease (p < 0.05) retained air and mean grade of microbubbles to 14% and 1.3 +/- 0.8 in group 1, and to 10% and 0.8 +/- 0.8 in group 2, without statistical difference between the two groups. Despite the help of TEE, manual attempts to eradicate retained air were unsuccessful in five patients (three in group 1, two in group 2).

CONCLUSIONS

The use of aortic ultrasonic probe allowed to reduce the amount of microbubbles. TEE was a useful tool not only for the detection of retained air but also for locating it, and guiding the procedure to eliminate it.

[Aneurysms of the left ventricle without atheromatous coronary artery disease. Apropos of 2 cases]

Left ventricular aneurysms are usually secondary to myocardial infarction with atheromatous coronary artery disease. The authors report two rare cases of non-atheromatous left ventricular apical aneurysms. The first case was clearly post-traumatic but the diagnosis in the second case was more difficult. The authors discuss the aetiological diagnosis of these rare non-atheromatous aneurysms in adults and the therapeutic management with respect to these two cases and a review of the literature.

Thoracoscopic approach to implantable cardioverter defibrillator patch electrode implantation

Even if transvenous lead system for automatic implantable cardioverter defibrillators (ICDs) has been one of the main surgical advances in the recent past, its major limitation is the high defibrillation thresholds in some cases. Thus, an additional patch may be required and implanted either in a subcutaneous position or in an epicardial position. We describe another possibility: the implantation of extrapericardial patch under video-thoracoscopic control. This new technique allows a deep implantation of the whole material without thoracotomy. Seven patients were included in our preliminary experience. During defibrillation threshold evaluation, two patients required 34 J with the single transvenous lead system, and five patients were not defibrillated with the single lead system; therefore, they required a 300-J external rescue shock. We decided to implant an additional patch in those seven patients with high defibrillation thresholds. This patch was inserted into the pleural cavity through a left subcostal incision. Under video thoracoscopy, it was positioned and stitched onto the pericardium. The defibrillation generator was then implanted through the left subcostal incision in a subdiaphragmatic space. As a result, preoperative defibrillation thresholds were significantly reduced (14.29 +/- 3.45 J, mean +/- SD) and remained stable during follow-up controls (eighth day and second month). Long-term follow-up (14 +/- 4.5 months) was uneventful, with an excellent tolerance for the patients. In conclusion, extrapericardial implantation of defibrillation patches under video thoracoscopy is an easy technique that allows low defibrillation thresholds.