Management of Coronary Artery Aneurysms at the Time of Surgical Revascularization

BACKGROUND

Coronary artery aneurysms (CAAs) represent a rare pathology occurring in 1.5%-5% of routine coronary angiograms. Limited data exist on the management of CAA at the time of cardiac surgery.

MATERIALS AND METHODS

A single-institution retrospective review was performed on 53 patients who underwent cardiac surgery in the setting of atherosclerotic CAA between 1993 and 2015. Patients were stratified based on treatment strategy: exclusion and distal bypass (n = 26) versus revascularization alone (n = 27). Comparisons were made with respect to mortality, need for further/concomitant interventions, and long-term cardiac function including myocardial infarctions and congestive heart failure.

RESULTS

A total of 53 patients underwent cardiac surgery in the setting of CAA disease. Management strategies included ligation and bypass in 26 patients and distal bypass only in 27 patients (with four of the patients in this group undergoing coronary stenting across the aneurysm). There were no significant differences in patient demographics between the two groups. No significant difference was found in either 30-d (P = 0.74) or long-term mortality when exclusion of the CAA was performed compared with revascularization alone (P = 0.20). More exclusion procedures were performed earlier in the experience (median surgical date 2000), whereas revascularization alone predominated later in the experience (median surgical date 2007; P ≤ 0.001).

CONCLUSIONS

The practice of CAA exclusion, while still performed in selected cases, has largely been supplanted in patients undergoing revascularization. Exclusion does not appear to offer any advantage over isolated revascularization, supporting the current trends in managing this rare condition.

Domino heart transplant following heart-lung transplantation: a systematic review and meta-analysis

Background

The domino-donor operation occurs when a "conditioned" heart from the heart-lung transplant (HLT) recipient is transplanted into a separate heart transplant (HT) recipient. The purpose of this systematic review was to investigate the indications and outcomes associated with the domino procedure.

Methods

An electronic search was performed to identify all prospective and retrospective studies on the domino procedure in the English literature. Eight studies reported 183 HLT recipients and 263 HT recipients who were included in the final analysis.

Results

HLT indications included cystic fibrosis in 58% (95% CI: 27-84%) of recipients, primary pulmonary hypertension (PPH) in 17% (95% CI: 12-24%), bronchiectasis in 5% (95% CI: 3-10%), emphysema in 5% (95% CI: 0-45%), and Eisenmenger's syndrome in 4% (95% CI: 2-8%). HT indications included ischemic heart disease in 40% (95% CI: 33-47%), non-ischemic disease in 39% (95% CI: 25-56%), and re-transplantation in 10% (95% CI: 1-59%). The pooled mean pulmonary vascular resistance (PVR) in HT recipients was 3.05 Woods units (95% CI: 0.14-5.95). The overall mortality in the HLT group was 28% (95% CI: 18-41%) at an average follow-up of 15.68 months (95% CI: 0.82-30.54), and 35% (95% CI: 17-58%) in the HT group at an average follow-up of 37.26 months (95% CI: 6.68-67.84). Freedom from rejection in HT was 94% (95% CI: 75-99%) at 1 month, 77% (95% CI: 30-96%) at 6 months, and 41% (95% CI: 33-50%) at 1 year.

Conclusions

The domino procedure appears to be a viable option in properly selected patients that can be performed safely with acceptable outcomes.

Downregulation of BK channel function and protein expression in coronary arteriolar smooth muscle cells of type 2 diabetic patients

Aims

Type 2 diabetes (T2D) is strongly associated with cardiovascular morbidity and mortality in patients. Vascular large conductance Ca2+-activated potassium (BK) channels, composed of four pore-forming α subunits (BK-α), and four regulatory β1 subunits (BK-β1), are densely expressed in coronary arterial smooth muscle cells (SMCs) and play an important role in regulating vascular tone and myocardial perfusion. However, the role of BK channels in coronary microvascular dysfunction of human subjects with diabetes is unclear. In this study, we examined BK channel function and protein expression, and BK channel-mediated vasodilation in freshly isolated coronary arterioles from T2D patients.

Methods and results

Atrial tissues were obtained from 16 patients with T2D and 25 matched non-diabetic subjects during cardiopulmonary bypass procedure. Microvessel videomicroscopy and immunoblot analysis were performed in freshly dissected coronary arterioles and inside-out single BK channel currents was recorded in enzymatically isolated coronary arteriolar SMCs. We found that BK channel sensitivity to physiological Ca2+ concentration and voltage was downregulated in the coronary arteriolar SMCs of diabetic patients, compared with non-diabetic controls. BK channel kinetics analysis revealed that there was significant shortening of the mean open time and prolongation of the mean closed time in diabetic patients, resulting in a remarkable reduction of the channel open probability. Functional studies showed that BK channel activation by dehydrosoyasaponin-1 was diminished and that BK channel-mediated vasodilation in response to shear stress was impaired in diabetic coronary arterioles. Immunoblot experiments confirmed that the protein expressions of BK-α and BK-β1 subunits were significantly downregulated, but the ratio of BK-α/BK-β1 was unchanged in the coronary arterioles of T2D patients.

Conclusions

Our results demonstrated for the first time that BK channel function and BK channel-mediated vasodilation were abnormal in the coronary microvasculature of diabetic patients, due to decreased protein expression and altered intrinsic properties of BK channels.

Outcomes of surgery for infective endocarditis: a single-centre experience of 801 patients

OBJECTIVES

Infective endocarditis (IE) remains a life-threatening disease, despite the improvement in diagnostic and therapeutic measures. We reviewed our outcomes for all adults who underwent surgery for endocarditis at our centre.

METHODS

Between January 1995 and December 2013, 801 patients [586 men (73%)] underwent surgery for IE. Mean age was 60 ± 14.7 years. Native endocarditis (NE) was present in 372 patients (46%), and 379 (47%) patients had active IE. The mean follow-up period was 4.6 ± 4.75 years (maximum 20 years).

RESULTS

Single-valve endocarditis was present in 551 (69%) patients (392 aortic and 159 mitral). Multivalve involvement was present in 250 (31%) patients. Preoperative stroke was present in 149 (19%) patients, while 62 (8%) patients were on dialysis prior to surgery. Valve repair was possible in 122 (15%) patients, while 679 (85%) patients underwent valve replacement. Mechanical valves were used in 312 (39%) patients. Aortic homografts were used in 84 (10%) patients. Early mortality occurred in 64 (8%) patients. Overall survival at 5, 10 and 20 years was 68%, 45% and 8.4%, respectively. Postoperative stroke occurred in 16 (2%) patients, while 59 (7%) patients required new dialysis postoperatively. Multivariate analysis revealed active IE (P = 0.002), preoperative dialysis (P = 0.007), previous coronary artery bypass grafting (P = 0.001), root abscess (P = 0.006) and tricuspid valve or multivalve involvement (P = 0.002) to be predictors of early mortality. The need for dialysis (P < 0.001), previous coronary artery bypass grafting (P < 0.001) and mitral valve (P = 0.002) and tricuspid valve/multivalve involvement (P < 0.001) were significant predictors of late mortality.

CONCLUSIONS

Active IE is associated with high perioperative mortality especially with multivalve and aortic root involvement. Preoperative stroke has no impact on perioperative mortality. Long-term survival for those who survived the immediate postoperative period is satisfactory, and mechanical valves are associated with the best long-term survival.

Predictors and Clinical Outcomes of Vasoplegia in Patients Bridged to Heart Transplantation With Continuous-Flow Left Ventricular Assist Devices

Background

The presence of a durable left ventricular assist device (LVAD) is associated with increased risk of vasoplegia in the early postoperative period following heart transplantation (HT). However, preoperative predictors of vasoplegia and its impact on survival after HT are unknown. We sought to examine predictors and outcomes of patients who develop vasoplegia after HT following bridging therapy with an LVAD.

Methods and Results

We identified 94 patients who underwent HT after bridging with continuous‐flow LVAD from 2008 to 2018 at a single institution. Vasoplegia was defined as persistent low vascular resistance requiring ≥2 intravenous vasopressors within 48 hours after HT for >24 hours to maintain mean arterial pressure >70 mm Hg. Overall, 44 patients (46.8%) developed vasoplegia after HT. Patients with and without vasoplegia had similar preoperative LVAD, echocardiographic, and hemodynamic parameters. Patients with vasoplegia were significantly older; had longer LVAD support, higher preoperative creatinine, longer cardiopulmonary bypass time, and higher Charlson comorbidity index; and more often underwent combined organ transplantation. In a multivariate logistic regression model, older age (odds ratio: 1.08 per year; P=0.010), longer LVAD support (odds ratio: 1.06 per month; P=0.007), higher creatinine (odds ratio: 3.9 per 1 mg/dL; P=0.039), and longer cardiopulmonary bypass time (odds ratio: 1.83 per hour; P=0.044) were independent predictors of vasoplegia. After mean follow‐up of 4.0 years after HT, vasoplegia was associated with increased risk of all‐cause mortality (hazard ratio: 5.20; 95% CI, 1.71–19.28; P=0.003).

Conclusions

Older age, longer LVAD support, impaired renal function, and prolonged intraoperative CPB time are independent predictors of vasoplegia in patients undergoing HT after LVAD bridging. Vasoplegia is associated with worse prognosis; therefore, detailed assessment of these predictors can be clinically important.

Robotic Mitral Valve Repair: Indication for Surgery Does Not Influence Early Outcomes

OBJECTIVE

To evaluate the outcomes of robotic mitral valve repair (MVr) by primary indication per American Heart Association guidelines for surgery: class I vs class IIa.

PATIENTS AND METHODS

From January 1, 2008, through September 30, 2016, 603 patients underwent robotic MVr for severe primary mitral regurgitation. Medical records of 576 consenting patients were retrospectively reviewed to determine the primary indication for surgery. Patients were stratified into class I or class IIa, and preoperative, intraoperative, and postoperative variables were compared.

RESULTS

Of 516 patients, 428 (83%) had class I indication and 88 (17%) had class IIa indication for surgery. Preoperatively, no significant differences were observed between both cohorts. Importantly, a significantly higher number of patients with class I indication underwent MVr for bileaflet prolapse (172 of 428 [40%] vs 21 of 88 [25%]; P=.03). Early MVr outcomes indicated recurrent mitral regurgitation (moderate or greater) in only 12 of 576 (2%), and no significant differences were observed between classes (P=.23). Apart from parameters for ventricular size, all other intraoperative and postoperative variables were comparable between both cohorts.

CONCLUSION

Comparable outcomes were indicated across all classes of indications for MVr surgery. These results continue to support the use of this surgical technique, even in less sick patients. Early referral along with more extensive robotic MVr experience will likely result in further improvements in long-term outcomes.

Open hemiarch versus clamped ascending aorta replacement for aortopathy during initial bicuspid aortic valve replacement

BACKGROUND

There is controversy regarding the extent of aortic resection necessary in patients with aortopathy related to bicuspid aortic valve disease. To address this issue, we reviewed our experience in patients undergoing ascending aorta replacement during bicuspid aortic valve replacement.

METHODS

We reviewed 702 patients who underwent ascending aorta replacement at the time of initial nonemergent native bicuspid aortic valve replacement at our institution between January 2000 and June 2017. Treatment cohorts included an open hemiarch replacement group (n = 225; 32%) and a clamped ascending aorta replacement group (n = 477; 68%).

RESULTS

Median patient age was 60 years (interquartile range [IQR], 51-67 years), female sex was present in 113 patients 16%, ejection fraction was 62% (IQR, 56%-66%), and aortic arch diameter was 33 mm (IQR, 29-36 mm). Cardiopulmonary bypass time was longer in the hemiarch replacement group (188 minutes vs 97 minutes; P < .001). Procedure-related complications (36%) and mortality (<1%) were similar in the 2 groups; however, the hemiarch group had an increased odds of blood transfusion (odds ratio, 1.62; 95% confidence interval [CI], 1.15-2.28; P = .006). The median duration of follow-up was 6.0 years (95% CI, 5.3-6.8 years). Overall survival was 94 ± 1% at 5 years and 80 ± 2% at 10 years. Multivariable analysis demonstrated similar survival in the 2 groups (hazard ratio, 0.83; 95% CI, 0.51-1.33; P = .439). No repeat aortic arch operations were done for aortopathy over the duration of clinical follow-up.

CONCLUSIONS

Compared with patients in the clamped ascending aorta replacement group, patients in the hemi-arch replacement group had longer cardiopulmonary bypass and aortic cross-clamp times, along with an increased risk of blood transfusion, but similar freedom from repeat aortic arch operation and survival. We identified no advantage of performing hemiarch replacement in the absence of aortic arch dilation.

Repeat Coronary Bypass Surgery or Percutaneous Coronary Intervention After Previous Surgical Revascularization

OBJECTIVE

To assess long-term survival with repeat coronary artery bypass grafting (RCABG) or percutaneous coronary intervention (PCI) in patients with previous CABG.

METHODS

From January 1, 2000, through December 31, 2013, 1612 Mayo Clinic patients underwent RCABG (n=215) or PCI (n=1397) after previous CABG. The RCABG cohort was grouped by use of saphenous vein grafts only (n=75), or with additional arterial grafts (n=140); the PCI cohort by, bare metal stents (BMS; n=628), or drug-eluting stents (DES; n=769), and by the treated target into native coronary artery (n=943), bypass grafts only (n=338), or both (n=116). Multivariable regression and propensity score analysis (n=280 matched patients) were used.

RESULTS

In multivariable analysis, the 30-day mortality was increased in RCABG versus PCI patients (hazard ratio [HR], 5.32; 95%CI, 2.34-12.08; P<.001), but overall survival after 30 days improved with RCABG (HR, 0.72; 95% CI, 0.55-0.94; P=.01). Internal mammary arteries were used in 61% (129 of 215) of previous CABG patients and improved survival (HR, 0.82; 95% CI, 0.69-0.98; P=.03). Patients treated with drug-eluting stent had better 10-year survival (HR, 0.74; 95% CI, 0.59-0.91; P=.001) than those with bare metal stent alone. In matched patients, RCABG had improved late survival over PCI: 48% vs 33% (HR, 0.57; 95% CI, 0.35-0.91; P=.02). Compared with RCABG, patients with PCI involving bypass grafts (n=60) had increased late mortality (HR, 1.62; 95% CI, 1.10-2.37; P=.01), whereas those having PCI of native coronary arteries (n=80) did not (HR, 1.09; 95% CI, 0.75-1.59; P=.65).

CONCLUSION

RCABG is associated with improved long-term survival after previous CABG, especially compared with PCI involving bypass grafts.

Diastolic Pulmonary Gradient as a Predictor of Right Ventricular Failure After Left Ventricular Assist Device Implantation

Background

Diastolic pulmonary gradient (DPG) was proposed as a better marker of pulmonary vascular remodeling compared with pulmonary vascular resistance (PVR) and transpulmonary gradient (TPG). The prognostic significance of DPG in patients requiring a left ventricular assist device (LVAD) remains unclear. We sought to investigate whether pre‐LVAD DPG is a predictor of survival or right ventricular (RV) failure post‐LVAD.

Methods and Results

We retrospectively reviewed 268 patients who underwent right heart catheterization before LVAD implantation from 2007 to 2017 and had pulmonary hypertension because of left heart disease. Patients were dichotomized using DPG ≥7 mm Hg, PVR ≥3 mm Hg, or TPG ≥12 mm Hg. The associations between these parameters and all‐cause mortality or RV failure post LVAD were assessed with Cox proportional hazards regression and Kaplan–Meier analyses. After a mean follow‐up time of 35 months, elevated DPG was associated with increased risk of RV failure (hazard ratio [HR]: 3.30; P=0.004, for DPG ≥7 versus DPG <7), whereas elevated PVR (HR 1.85, P=0.13 for PVR ≥3 versus PVR <3) or TPG (HR 1.47, P=0.35, for TPG ≥12 versus TPG <12) were not associated with the development of RV failure. Elevated DPG was not associated with mortality risk (HR 1.16, P=0.54, for DPG ≥7 versus DPG <7), whereas elevated PVR, but not TPG, was associated with higher mortality risk (HR 1.55; P=0.026, for PVR ≥3 versus PVR <3).

Conclusions

Among patients with pulmonary hypertension because of left heart disease requiring LVAD support, elevated DPG was associated with RV failure but not survival, while elevated PVR predicted mortality post LVAD implantation.

Long-Term Sirolimus for Primary Immunosuppression in Heart Transplant Recipients

BACKGROUND

Small studies have reported superiority of sirolimus (SRL) over calcineurin inhibitor (CNI) in mitigating cardiac allograft vasculopathy (CAV) after heart transplantation (HT). However, data on the long-term effect on CAV progression and clinical outcomes are lacking.

OBJECTIVES

The aim of this study was to test the long-term safety and efficacy of conversion from CNI to SRL as maintenance therapy on CAV progression and outcomes after HT.

METHODS

A cohort of 402 patients who underwent HT and were either treated with CNI alone (n = 134) or converted from CNI to SRL (n = 268) as primary immunosuppression was analyzed. CAV progression was assessed using serial coronary intravascular ultrasound during treatment with CNI (n = 99) and after conversion to SRL (n = 235) in patients who underwent at least 2 intravascular ultrasound studies.

RESULTS

The progression in plaque volume (2.8 ± 2.3 mm³/mm vs. 0.46 ± 1.8 mm³/mm; p < 0.0001) and plaque index (plaque volume-to-vessel volume ratio) (12.2 ± 9.6% vs. 1.1 ± 7.9%; p < 0.0001) were significantly attenuated when treated with SRL compared with CNI. Over a mean follow-up period of 8.9 years from time of HT, all-cause mortality occurred in 25.6% of the patients and was lower during treatment with SRL compared with CNI (adjusted hazard ratio: 0.47; 95% confidence interval: 0.31 to 0.70; p = 0.0002), and CAV-related events were also less frequent during treatment with SRL (adjusted hazard ratio: 0.35; 95% confidence interval: 0.21 to 0.59; p < 0.0001). Further analyses suggested more attenuation of CAV and more favorable clinical outcomes with earlier conversion to SRL (≤2 years) compared with late conversion (>2 years) after HT.

CONCLUSIONS

Early conversion to SRL is associated with attenuated CAV progression and with lower long-term mortality and fewer CAV-related events compared with continued CNI use.

One Hundred and Counting: Dr Dwight C. McGoon's Enduring Legacy

Dr Dwight C. McGoon, a prolific surgeon at the Mayo Clinic in Rochester, Minnesota, achieved an amazing feat during the early days of cardiac surgery. In 1965, he reported a series of 100 consecutive aortic valve replacements with no in-hospital mortality. As a pioneer in adult and congenital cardiac surgery, his other contributions included novel uses of left ventricular and biventricular extracardiac conduits and describing repairs for mitral regurgitation resulting from ruptured chordae, transposition of the great arteries, truncus arteriosus, pulmonary stenosis, and pulmonary atresia. More than 50 years later, Dr McGoon is still remembered for his technical prowess, innovation, mentorship, and humanism.

Why do lung transplant patients discontinue triazole prophylaxis?

BACKGROUND

Lung transplant recipients are prone to invasive fungal infections prompting many transplant centers to use prolonged triazole antifungal prophylaxis. From a practical standpoint, it is unclear if lung transplant recipients are able to continue prolonged or lifelong prophylaxis without premature discontinuation from side effects, drug interactions, development of fungal disease, or medication cost. We examined the number of patients that are able to reach a prophylactic endpoint and understand the reasons for early termination.

METHODS

We conducted a retrospective chart review of all lung and heart-lung transplant patients at Mayo Clinic Rochester from May 1, 2002 to December 31, 2017. Type, duration, and reason for discontinuation of triazole prophylaxis were examined.

RESULTS

During the study period, 193 patients underwent lung or heart-lung transplantation. Itraconazole, voriconazole, and posaconazole were given to 180, 73, and 60 post-transplant patients, respectively. Providers switched itraconazole to another prophylactic antifungal medication for reasons other than prophylactic completion in 61.8% (126 out of 204) of exposure episodes; this was similar with voriconazole (68.8%, 53 out of 77, P = 0.41). Posaconazole was actively discontinued significantly less often (18.3%, 11 out of 60, P < 0.05). The most common reasons for discontinuing itraconazole were malabsorption (15.5% of exposure episodes) and concern for breakthrough fungal infection (10.2%). In comparison, the most common reason for voriconazole discontinuation was side effect or intolerance (54.5% of VR exposure episodes vs 9.8% of IT exposure episodes, P < 0.05).

CONCLUSIONS

Itraconazole and posaconazole appeared to have fewer side effects prompting discontinuation than voriconazole, but itraconazole was discontinued more often because of malabsorption and clinical suspicion of fungal infections.

Early Outcomes of Cardiac Surgery in Patients with Noonan Syndrome

There is a paucity of cardiac surgery outcomes data for patients with Noonan syndrome (NS). Our objective was to evaluate early results in these patients. Between January 1999 and December 2015, 29 patients (18 males, 62%) with NS underwent cardiac surgery at our institution. Mean age was 23 ± 17.9 years; 12 (41%) were under 18 years of age. Fourteen patients (48%) had prior sternotomies. The primary operations for the main diagnosis were pulmonary valve/conduit replacement/repair (n = 14, 48%), septal myectomy for obstructive hypertrophic cardiomyopathy (n = 7, 24%), aortic valve replacement/repair (n = 4, 14%), atrial septal defect (ASD) repair (n = 2, 7%), and cardiac transplantation (n = 2, 7%). Concomitant procedures were performed in 24 patients (83%), most commonly right ventricular outflow tract reconstruction (n = 13, 45%), mitral valve repair/replacement (n = 7, 24%), and ASD repair (n = 6, 21%). Mean bypass and cross-clamp times were 88.8 ± 51 minutes and 54.7 ± 67 minutes, respectively. There was 1 early death (3%). Postoperative morbidity occurred in 18 patients (62%), most commonly arrhythmias (n = 14, 48%) or respiratory insufficiency/pneumonia (n = 6, 21%). There were 2 early reoperations and 4 early readmissions. Univariate factors associated with morbidity included male gender (P = 0.03) and longer cross-clamp time (P = 0.02). Median length of hospital stay was 6 days (interquartile range 5-10.5 days). Patients with NS frequently have multiple cardiac lesions requiring a broad spectrum of operations. Early mortality is low despite procedure complexity. Although early postoperative morbidity is common, patients overall do well with reasonable hospital lengths of stay. Additional studies are needed to evaluate long-term outcomes and quality of life.

Patient Experience After Cardiac Surgery: Identifying Areas for Improvement

BACKGROUND

The Hospital Consumer Assessment of Healthcare Providers and Systems (HCAHPS) is a publicly reported survey of patient experience with in-hospital care. We reviewed institutional HCAHPS survey data to assess our patients' experiences after cardiac surgery and to identify targets for practice improvement.

METHODS

We reviewed data from patients undergoing the most common cardiac operations, with dismissal from October 1, 2012 to September 30, 2015. We used top-box methodology to combine survey results into nine domains, including the global (composite) hospital rating, dichotomized as high versus low. Multivariable logistic regression analysis was used to evaluate the independent associations of variables with low global ratings. Key driver analysis using domain means and Spearman correlation between the global rating and the eight other domains identified targets for quality improvement.

RESULTS

Among 1,315 surveyed patients a low global hospital rating was independently associated with low perceived overall health (fair or poor vs excellent; odds ratio [OR], 5.4; p = 0.001), younger age (18 to 59 vs ≥70 years; OR, 1.6; p = 0.048), prolonged length of stay (OR, 1.6; p = 0.02), and robotic mitral valve (MV) repair (robotic vs open repair; OR, 2.4; p = 0.045). Patients undergoing transcatheter aortic valve replacement (TAVR) reported global ratings similar to that of patients with open aortic valve operations (OR, 0.9; p = 0.64). Key drivers of patient experience were care transitions and communication regarding medications.

CONCLUSIONS

The primary targets of improvement for our institution are care transitions and communications regarding medications. The less-invasive procedures (robotic MV repair, TAVR) were not independently associated with higher patient-experience scores.