Knowledge, attitudes, and practice preferences in the surgical threshold for ascending aortic aneurysm among Canadian cardiac surgeons

OBJECTIVE

The survey aimed to assess the practice patterns of Canadian cardiac surgeons on the size threshold at which patients with ascending aortic aneurysm would be offered surgery.

METHODS

A 18-question electronic survey was electronically distributed to 148 practicing cardiac surgeons in Canada via email from January to August 2020. Questions presented clinical scenarios focusing on modifying a single variable, and respondents were asked to identify their surgical size threshold for each of the clinical scenarios.

RESULTS

The individual response rate was 62.0% (91/148) and institutional response rate was 89.3% (25/29). For an incidental asymptomatic ascending aortic aneurysm in a 60-year-old otherwise-healthy male patient with a tricuspid aortic valve and bicuspid aortic valve of 1.9 m², 20.2% of the respondents would recommend surgery when the aneurysm was <5.5 cm. A significant number of surgeons modified their surgical threshold in response to changes to BSA, bicuspid aortic valve, growth rate, age, occupation, symptom, and family history (P < .01). Notably, if the patient had a bicuspid aortic valve, 41.0% of respondents lowered their threshold for surgery, with only 43.0% recommending surgery at ≥5.5 cm (P < .01).

CONCLUSIONS

Practice variations exist in the current size threshold for surgery of ascending aortic aneurysms in Canada. These differences between surgeons are further accentuated in the context of bicuspid aortic valve, smaller body stature, younger age, low growth rate, family history, and for the performance of isometric exercise. These represent important areas where future prospective studies are required to inform best practice.

Long-Term Follow-Up of Outcomes With F-18-Fluorodeoxyglucose Positron Emission Tomography Imaging–Assisted Management of Patients With Severe Left Ventricular Dysfunction Secondary to Coronary Disease

Background—

Whether viability imaging can impact long-term patient outcomes is uncertain. The PARR-2 study (Positron Emission Tomography and Recovery Following Revascularization) showed a nonsignificant trend toward improved outcomes at 1 year using an F-18-fluorodeoxyglucose positron emission tomography (PET)–assisted strategy in patients with suspected ischemic cardiomyopathy. When patients adhered to F-18-fluorodeoxyglucose PET recommendations, outcome benefit was observed. Long-term outcomes of viability imaging–assisted management have not previously been evaluated in a randomized controlled trial.

Methods and Results—

PARR-2 randomized patients with severe left ventricular dysfunction and suspected CAD being considered for revascularization or transplantation to standard care (n= 195) versus PET-assisted management (n=197) at sites participating in long-term follow-up. The predefined primary outcome was time to composite event (cardiac death, myocardial infarction, or cardiac hospitalization). After 5 years, 105 (53%) patients in the PET arm and 111 (57%) in the standard care arm experienced the composite event (hazard ratio for time to composite event =0.82 [95% confidence interval 0.62–1.07]; P =0.15). When only patients who adhered to PET recommendations were included, the hazard ratio for the time to primary outcome was 0.73 (95% confidence interval 0.54–0.99; P =0.042).

Conclusions—

After a 5-year follow-up in patients with left ventricular dysfunction and suspected CAD, overall, PET-assisted management did not significantly reduce cardiac events compared with standard care. However, significant benefits were observed when there was adherence to PET recommendations. PET viability imaging may be best applied when there is likely to be adherence to imaging-based recommendations.

Clinical Trial Registration—

URL: http://www.clinicaltrials.gov . Unique identifier: NCT00385242.

Cerebral microembolization after bioprosthetic aortic valve replacement: comparison of warfarin plus aspirin versus aspirin only

BACKGROUND

No human physiological data exists on whether aspirin only is as effective as warfarin plus aspirin in preventing cerebral microembolization in the early postoperative period after bioprosthetic aortic valve replacement (bAVR).

METHODS AND RESULTS

We prospectively enrolled 56 patients who had no other indication for oral anticoagulation, who underwent bAVR and received, in an open-label fashion, either daily warfarin (for INR 2.0-3.0) plus 81 mg of aspirin (n=28) or 325 mg of aspirin only (n=28). Cerebral microembolization was quantified at 4 hours (baseline) and at 1 month postoperatively, by recording 1-hour bilateral middle cerebral artery (MCA) microembolic signals (MES). Platelet-function analysis (PFA) of closure times (CT) on collagen was also used as a marker of platelet-dependent activation. Follow-up to 1 year was complete. Preoperative demographics and baseline platelet function were equivalent in both groups. There was no mortality, stroke, or transient ischemic attack at 1 year in either group. No significant differences were found in the proportion of patients with MES among those receiving warfarin plus aspirin versus aspirin only, at baseline (68% versus 82%, respectively; P=0.4) and at 1 month (46% versus 43%; P=1.0) after bAVR. The total MES and PFA were also equivalent between groups, at baseline and follow-up.

CONCLUSIONS

Early after bAVR, the effects of these 2 antithrombotic regimens on cerebral microembolization and platelet function are equivalent. These data bring new mechanistic support to the premise that aspirin only may safely be used early after bAVR in patients who have no other indication for oral anticoagulation.

Long-Term Clinical and Hemodynamic Performance of the Hancock II Versus the Perimount Aortic Bioprostheses

Background— The Medtronic Hancock II and the Carpentier-Edwards Perimount are among the world’s most commonly used aortic bioprostheses. However, a direct comparison of their clinical performance is lacking. To minimize biases inherent to between-center comparisons, we examined these prostheses within a large, contemporary, single-center cohort.

Methods and Results— Between 1990 and 2007, 1659 patients (mean age, 73.1±9.3 years) underwent aortic valve replacement with either the Hancock II (N=1021) or the Perimount (N=638). Patients were prospectively followed-up with serial clinic visits and echocardiograms for up to 16 years (mean, 5.0±3.3 years). There was no significant difference in aortic root size preoperatively ( P =0.7). Aortic root enlargement was more commonly performed with the Perimount ( P <0.001), and the manufacturer valve size of the implanted prosthesis was larger with the Hancock II ( P <0.001). Postoperatively, peak and mean transprosthesis gradients were higher for the Hancock II (32.7±0.7 and 16.0±0.3 mm Hg, respectively) than for the Perimount (24.9±0.7 and 13.4±0.4 mm Hg, respectively; P <0.001). However, no difference in left ventricular mass regression was observed at late follow-up ( P =0.9). Unadjusted 10-year survival was 59.4%±2.4% for the Hancock II and 70.2%±3.8% for the Perimount ( P =0.07). Multivariable predictors of survival did not include prosthesis type ( P =0.2).

Conclusions— For the same manufacturer valve size, the Perimount is larger, which may warrant enlarging the aortic root more often, and it is associated with better hemodynamics than the Hancock II. These differences do not impact survival or left ventricular mass regression, and the long-term clinical performances of the Hancock II and Perimount bioprostheses are equivalent.

The impact of patient–prosthesis mismatch on late outcomes after mitral valve replacement

OBJECTIVES

The incidence of patient-prosthesis mismatch after mitral valve replacement and its effect on late outcomes have remained unclear. This study was conducted to determine the impact of patient-prosthesis mismatch on recurrent congestive heart failure, postoperative pulmonary hypertension, and late survival after mitral valve replacement.

METHODS

Between 1985 and 2005, 884 patients, with a mean age 63 +/- 12 years, underwent mitral valve replacement (657 mechanical, 227 bioprosthesis) with contemporary prostheses. Mean clinical and echocardiographic follow-up was 5.1 +/- 4.1 years (4344 patient-years). Patient-prosthesis mismatch was defined as an indexed effective orifice area of 1.25 cm2/m2 or less. Parametric and nonparametric analyses were used to determine predictors of outcomes.

RESULTS

The incidence of patient-prosthesis mismatch was 32%. Predictors of recurrent congestive heart failure included low indexed effective orifice area, low ejection fraction, elevated postoperative mean mitral gradient, and use of a bioprosthesis (P < or = .05). Postoperative pulmonary hypertension was associated with small mitral size, elevated mean mitral gradient, low ejection fraction, and atrial fibrillation (P < or = .05); indexed effective orifice area did not predict postoperative pulmonary hypertension (P = .89). Poor late survival was predicted by low indexed effective orifice area (< or =1.25 cm2/m2), New York Heart Association class 3 or 4, elevated right ventricular pressure, stroke, older age, coronary artery disease, and bioprosthesis use (P < or = .05). Survival for patients with patient-prosthesis mismatch versus those without patient-prosthesis mismatch at 1, 3, 5, and 10 years was 91% versus 95%, 85% versus 90%, 78% versus 86%, and 65% versus 75%, respectively (P = .05).

CONCLUSIONS

Patient-prosthesis mismatch after mitral valve replacement is not uncommon; it is associated with recurrence of congestive heart failure and postoperative pulmonary hypertension and independently affected late survival. This study emphasizes the importance of implanting a sufficiently large prosthesis in adult patients undergoing mitral valve replacement.

Management of acute severe perioperative failure of cardiac allografts: a single-centre experience with a review of the literature

BACKGROUND

Early graft failure is associated with high mortality and is the main cause of death within the first 30 days after transplantation. The purpose of the present study was to examine the investigators' experience of severe perioperative acute graft failure and to review the literature.

METHODS

Nine of 385 cardiac transplants (2.3%) performed from 1984 through 2005 developed severe perioperative acute graft failure either in the operating room or within 24 h after cardiac transplantation. Four patients had primary graft failure, two had right heart failure secondary to pulmonary hypertension, one had hyperacute rejection, one had accelerated acute rejection and one possibly sustained a particulate coronary embolus intraoperatively.

RESULTS

All except the two patients who had right heart failure secondary to pulmonary hypertension received mechanical circulatory support. Three patients were supported with total artificial hearts, two patients received a left ventricular assist device, one patient was supported with extracorporeal life support followed by a right ventricular assist device when the left ventricle recovered, and one patient was supported for several hours with cardiopulmonary bypass. Three patients were retransplanted after mechanical circulatory support, but only one survived. Only one of the nine patients (11%) survived; this patient was supported with a total artificial heart followed by retransplantation.

CONCLUSION

The outcome of severe perioperative acute graft failure is very poor. Mechanical circulatory support and retransplantation are not as successful as in other situations. Due to the shortage of donors and poor outcomes, retransplantation for hyperacute rejection is not advisable.

Combined atrial fibrillation ablation with mitral valve surgery

BACKGROUND AND AIM OF THE STUDY

The study aim was to evaluate the efficacy and outcome of radiofrequency (RF) atrial fibrillation (AF) ablation in patients undergoing mitral valve (MV) surgery.

METHODS

Between March 2002 and December 2004, 61 patients (mean age 65.4 +/- 10 years) underwent isolated endo-left atrial AF ablation using a unipolar RF device (Cardioblate; Medtronic, USA) in conjunction with 34 MV repairs and 27 MV replacements. AF was paroxysmal in 13 patients (21%), and permanent in 48 (79%), with a mean duration of 3.6 +/- 3.5 years. The etiology was degenerative in 35 patients (57%), rheumatic in 17 (28%), and ischemic in nine (17%). All patients received amiodarone postoperatively.

RESULTS

No patients died during the study, and there were no thromboembolic complications. All patients had intraoperative conversion. Forty-one patients (67%) presented with postoperative relapse; definitive conversion was achieved in 34 (83%) cases within three months. The overall success rate was 75.4% at 14 +/- 8.8 months; success was greater in the MV repair group (85%) than in the MV replacement group (66.7%), though not significantly so (p = 0.09). Factors associated with definitive conversion included smaller left atrial size (p = 0.007), decreased left ventricular end-diastolic diameter (p = 0.04), and NYHA class I (p = 0.05). Age, AF duration and etiology were not associated with conversion, but associated coronary artery bypass grafting showed a strong trend towards significance (p = 0.07). In these patients, AF duration did not predict conversion to sinus rhythm.

CONCLUSION

Combined AF ablation with MV surgery is safe and effective. Although AF ablation seems more beneficial with MV repair, the success rate may vary significantly according to patient characteristics.

Left Ventricular Assist Devices as Bridge to Heart Transplantation in Congestive Heart Failure with Pulmonary Hypertension

Severe pulmonary hypertension (PH) has been considered a significant contraindication to cardiac transplantation. Ongoing clinical experience, however, has shown that temporary support using left ventricular assist devices (LVADs) in these patients can result in significant reductions in PH. A comprehensive review of the available literature regarding the use of LVADs in heart failure patients with PH was conducted. The existing literature to date supports the use of LVADs in heart failure patients with PH and demonstrates that significant reductions in PH in these patients can be achieved. This subsequently allows for safe and effective cardiac transplantation in patients who were previously excluded from this modality. For heart failure patients with severe PH, the use of LVADs can provide significant benefits by significantly reducing PH and allowing subsequent staged transplantation.

Does taping control the foot during walking for people who have had a stroke?

This pilot study investigated the potential effects of inversion-control ankle taping on the timing and distribution of plantar pressures in the hemiplegic foot during the stance phase of gait. Five subjects with residual left hemiplegia after stroke and equinovarus foot posture participated in the single-case design study. The Emed-AT-2 force plate system was used to measure and analyse specific plantar pressure variables, including time to heel strike, contact area and maximum mean pressure under the total surface of the foot. Subjective reports of functional gait were also recorded. Descriptive statistics were calculated for the analysis of results.

All subjects achieved earlier heel-strike under the taped condition. Changes in other gait parameters appeared to depend on the individual subject characteristics. This study has identified beneficial effects and further research is warranted to confirm the use of ankle taping as a quick and affordable gait re-education tool after stroke.

Giant cell myocarditis: clinical presentation, bridge to transplantation with mechanical circulatory support, and long-term outcome

BACKGROUND

The multicenter Giant Cell Myocarditis Registry recorded 64 cases from 36 centers before 1996. The median transplant-free survival of 30 patients without immunosuppression was 3 months. Of 34 patients who received heart transplantations, 9 experienced recurrence of giant cell myocarditis in their transplanted hearts and 1 patient died.

METHODS

We reviewed our experience in 340 heart transplantations since 1984. Unexpected giant cell myocarditis was found in the explanted hearts of 7 patients (6 men and 1 female, aged 18-65 years).

RESULTS

The duration from the onset of symptoms to assist-device implant or transplantation ranged from 11 days to 9 years, whereas the time interval from referral or deterioration ranged from 2 days to 4 months. Four patients required mechanical circulatory support before surgery (total artificial hearts in 2 and left ventricular assist devices in 2), and 3 patients required inotropic drugs. Six patients are alive with no sign of recurrent giant cell myocarditis at 12 to 113 months after surgery. One patient died suddenly 75 months after surgery, and autopsy showed severe graft vascular disease with no recurrence of giant cell myocarditis. Surveillance, right ventricular endomyocardial biopsy specimens showed recurrent asymptomatic giant cell myocarditis in 3 patients at 5 to 13 months after surgery, and found recurrence in 1 patient 30 months after surgery. This patient received augmented immunosuppression.

CONCLUSIONS

Giant cell myocarditis often is not diagnosed before transplantation. It can present as dilated cardiomyopathy with late deterioration, or it can present with rapid hemodynamic deterioration. In our experience, these patients can be bridged successfully to transplant with mechanical circulatory assist. Giant cell myocarditis may recur after transplantation but may respond to augmented immunosuppression.

Safety, tolerability, and efficacy of cyclosporine microemulsion in heart transplant recipients: a randomized, multicenter, double-blind comparison with the oil-based formulation of cyclosporine--results at 24 months after transplantation

BACKGROUND

The widespread use of cyclosporine has improved the survival of cardiac transplant patients as a result of reduced morbidity and mortality from rejection and infection. The original oil-based form of cyclosporine demonstrated unpredictable absorption resulting in an increased frequency of acute and chronic rejection in patients with poor bioavailability. The primary end. points of the present, prospective, randomized multicenter, double-blind trial were to compare the efficacy of the micro-emulsion form of cycolsporine (CsA-NL) with the oil-based formulation as determined by cardiac allograft and recipient survival and the incidence and severity of the acute rejection episodes and to determine the safety and tolerability of CsA-NL compared with Sandimmune CsA-(SM) in the study population. The 6-month analysis of the study showed reduced number of CsA-NL patients requiring antilymphocyte antibody therapy for rejection, fewer International Society of Heart and Lung Transplantation grade > or =3A rejections in female patients and fewer infections. Our report represents the final analysis of the results 24 months after transplantation.

METHODS

A total of 380 patients undergoing de novo cardiac transplants at 24 centers in the United States, Canada, and Europe were enrolled in this double-blind, randomized trial evaluating the efficacy and safety of CsA-NL versus CsA-SM. Acute allograft rejection was diagnosed by endomyocardial biopsy and graded according to the International Society of Heart and Lung Transplantation nomenclature. Kaplan-Meier analysis and Fisher's exact test were used for comparisons between groups.

RESULTS

After 24 months, allograft and recipient survival were identical in both groups. There were fewer CsA-NL patients (6.9%) requiring antilymphocyte antibody therapy for rejection than in the CsA-SM-treated patient group (17.7%, P=0.002). There were fewer discontinuations of study drug for treatment failures in the CsA-NL groups (7; 3.7%) compared with the CsA-SM group (18; 9.4%, P=0.037). The average corticosteroid dose was lower in the CsA-NL group (0.37 mg/kg/day) compared with the CsA-SM group (0.48 mg/kg/day, P=0.034) over the 24-month study period. Overall, there was no difference in blood pressure or creatinine between the two study groups.

CONCLUSIONS

The final results of this multi-center, randomized study of two forms of cyclosporine confirmed that there were fewer episodes of rejection requiring antilymphocyte antibodies and fewer study discontinuations for treatment failures in CsA-NL-treated patients compared to those treated with CsA-SM. The use of CsA-NL did not predispose these patients to a higher risk of adverse events.

Three cases of platelet alloimmunisation associated with the presence of a novel platelet-specific antibody

BACKGROUND AND OBJECTIVES

In three cases of platelet alloimmunisation, a platelet-specific alloantibody was detected which could not be classified within the known human platelet alloantigen or HLA systems. The first case was of a family in which two siblings suffered neonatal alloimmune thrombocytopenia at birth. In the second case, the newborn was suffering from phocomelia with hypoplastic thrombocytopenia. The third case was a male who became refractory to transfusions of HLA-matched platelets after a related bone marrow transplantation.

MATERIALS AND METHODS

The serum samples were investigated by: enzyme-linked immunosorbent assay, platelet suspension immunofluorescence test (PSIFT), monoclonal antibody immobilisation of platelet antigens assay (MAIPA), and by the lymphocytotoxicity test.

RESULTS

The antibody gave positive reactions with 26% of normal donor platelets. Surprisingly, no platelet-specific antibody was detected by PSIFT or by MAIPA and there was no evidence found to support classifying the antibody within the HLA system.

CONCLUSION

The reactivity pattern of the antibody detected and the clinical presentation of the three cases described, strongly suggest the presence of an additional platelet-specific alloantigen system.

International experience with the CardioWest total artificial heart as a bridge to heart transplantation

As the number of potential heart donors remains constant and the number of potential recipients continuous to increase, the need for circulatory devices to bridge patients becomes more important. The CardioWest total artificial heart (TAH) is a pneumatic, implantable system that totally replaces the failing ventricles. It has been utilized worldwide as a bridge to heart transplantation in 79 patients. There were 73 males and six females who received the TAH. Currently three patients remain on the device waiting for transplantation. A total of 55 patients (70%) were transplanted of which 50 survived (91% of patients transplanted) and were discharged home. Idiopathic/dilated cardiomyopathy was the most common etiology followed by ischemic cardiomyopathy. The mean duration of implant was 34 days (range 0-186 days) and the mean age of the group was 45 years (range 16-62 years). Twenty-one patients died while on the device. Multiple organ failure was the major cause of death. There were a total of 255 complications in this group that included reoperation, bleeding, hepatic failure, renal failure, respiratory failure, neurologic events, thromboembolic events, infections, device malfunction, and fit complications. This represented a mean complication rate of three events per patient. The survival rate for the CardioWest TAH of 91% of the patients who reached transplantation is an improvement over that of the Symbion registry (55% of those transplanted) probably as a result of a better patient selection and better control of the coagulation system. These results are also comparable to those survival results obtained with other biventricular and left ventricular assist devices currently available.

An immunocytochemical study of MHC class I expression on human Langerhans cells and melanocytes

Classical MHC class I glycoproteins (HLA-A, B, and C) present endogenous cytosolic peptide antigen fragments to CD8-positive T-cells. CD8-positive T-cell recognition and destruction of virus-infected cells are dependent on adequate cellular MHC class I expression. Constitutive MHC class I expression is ubiquitous, but known to be deficient on specific differentiated cell types which include hepatocytes, neurones, chondrocytes and myocytes. Although enabling assessment of MHC class I expression on individual cells, limitations of immunocytochemistry were encountered with this assessment on Langerhans cells and melanocytes. These dispersed intraepidermal cells were obscured by adjacent keratinocytes in sections immunostained for MHC class I glycoproteins. Initiatives designed to resolve the issue have included immunoelectron microscopy, cell culture techniques, and animal bone marrow chimera models. Despite the elegance of these techniques, the issue of MHC class I expression on Langerhans cells and melanocytes remains unresolved. In this immunocytochemical study, an alternative strategy was based upon the recognized deficiency of epithelial MHC class I expression within pilosebaceous adnexal units. Langerhans cells and melanocytes were therefore studied within this microenvironment of deficient MHC class I expression, using monomorphic and polymorphic MHC markers. Langerhans cells and melanocytes were demonstrated within pilosebaceous units of scalp skin by immunocytochemistry. Differentiation markers OKT6 (CD1a) and TMH1 defined Langerhans cells and melanocytes, respectively. Monomorphic MHC markers W6/32 and TAL IB5 defined invariant epitopes of HLA class I and II, respectively. Polymorphic MHC class I markers defined the HLA-Bw4 and HLA-Bw6 supertypic determinants. Constitutive MHC class I expression was shown to be deficient on Langerhans cells and melanocytes.

Bridge to transplantation with the CardioWest total artificial heart: the international experience 1993 to 1995

BACKGROUND

After reapproval by the Food and Drug Administration of the CardioWest total artificial heart for clinical investigation, an international study was started in January 1993 to ascertain the safety and efficacy of this device for bridging to heart transplantation. To date, 40 devices have been implanted in five centers.

METHODS

Retrospective data collection from participating centers provided enough material for analysis of patient selection, patient survival, adverse events, and comparison with contemporary devices used for bridge to transplantation.

RESULTS AND CONCLUSIONS

Twelve patients (30%) died after implantation and before transplantation after an average of 10.6 +/- 10 days of support. The major cause of death in this group was multiorgan failure. Twenty-eight patients (70%) were supported 36 +/- 36 days before transplantation. There were two deaths after transplantation (1 rejection, 1 multiorgan failure) leaving 26 patients (65% of the total patients and 93% of those who were transplanted) who survived to discharge from the hospital. There was one late death from rejection at one month post discharge. The mean survival time of the 25 surviving patients is 12 months. These results compare favorably with those of other contemporary devices used for bridge to transplantation.

The use of restraints

This article describes a flow chart created to help nurses identify interventions other than physical restraint. The decision flow chart comprises five charts, each addressing a common area of patient behavior often cited by nurses as justification for physical restraint in the long-term care setting: poor sitting posture, rigidity, wandering, agitation, and falls. The charts list possible reasons and causes for the behavior and give specific suggestions for interventions based on the identified cause.

Advantages of an off-Littrow mounting of an echelle grating

A phenomenon is described in which the size of the exit-slit image of the entrance slit is influenced by the angle at which an echelle grating is used. The phenomenon becomes significant only for large deviations from Littrow conditions. A mathematical treatment and experimental results are presented to show that proper exploitation of the effect results in simultaneous improvements in bandpass, range, and intensity for an echelle spectrometer.

The psyche and the skin

The concept of psychosomatic disorders has been undergoing great evolutionary changes during the past 20 to 30 years. There is no longer any significant or reasonable disagreement that the brain and body mutually interact, and the pathways of those interactions are being explored and explained. Enormous amounts of work are being done to unravel the workings of the brain, which is more complex than any other organ because of neural connections and networking of astronomic proportions.