Max Baghai

The Gap-Junctional Protein Connexin40 Is Elevated in Patients Susceptible to Postoperative Atrial Fibrillation

Background —Atrial fibrillation (AF), a cardiac arrhythmia arising from atrial re-entrant circuits, is a common complication after cardiac surgery, but the proarrhythmic substrate underlying the development of postoperative AF remains unclear. This study investigated the hypothesis that altered expression of connexins, the component proteins of gap junctions, is a determinant of a predisposition to AF. Methods and Results —The expression of the 3 atrial connexins–connexins 43, 40, and 45 —was analyzed at the mRNA and protein levels by Northern and Western blotting techniques and immunoconfocal microscopy in right atrial appendages from patients with ischemic heart disease who were undergoing coronary artery bypass surgery. Twenty percent of the patients subsequently developed AF, which allowed retrospective division of the samples into 2 groups, non-AF and AF. Connexin43 and connexin45 transcript and protein levels did not differ between the groups. However, connexin40 transcript and protein were expressed at significantly higher levels in the AF group. Connexin40 protein was markedly heterogeneous in distribution. Conclusions —Atrial myocardium susceptible to AF is distinguished from its nonsusceptible counterpart by elevated connexin40 expression. The heterogeneity of connexin distribution could give rise to different resistive properties and conduction velocities in spatially adjacent regions of tissue, which become enhanced and, hence, proarrhythmic the higher the overall level of connexin40.

Is Mitral Valve Repair Superior to Mitral Valve Replacement in Elderly Patients? Comparison of Short‐ and Long‐Term Outcomes in a Propensity‐Matched Cohort

Background Because of demographic changes, a growing number of elderly patients present with mitral valve (MV) disease. Although mitral valve repair (MV‐repair) is the “gold standard” treatment for MV disease, in elderly patients, there is controversy about whether MV‐repair is superior to mitral valve replacement. We reviewed results after MV surgery in elderly patients treated over the past 20 years. Methods and Results Our in‐hospital database was explored for patients who underwent MV surgery between 1994 and 2015. Survival data, obtained from the National Health Service central register, were complete for all patients. Of 1776 patients with MV disease, 341 were aged ≥75 years. Patients with repeat cardiac surgery, endocarditis, and concomitant aortic valve replacement were excluded. This yielded 221 MV‐repair and 120 mitral valve replacement patients. Concomitant procedures included coronary artery bypass grafting in 135 patients (39.6%) and tricuspid valve surgery in 50 patients (14.7%). Thirty‐day mortality was 5.4% (MV‐repair) versus 9.2% (mitral valve replacement, P=0.26). Overall 1‐ and 5‐year survival was 90.7%, 74.2% versus 81.3%, 61.0% (P<0.01). Median survival after MV‐repair was 7.8 years, close to 8.5 years (95% CI: 8.2–9.4) in the age‐matched UK population (ratio 0.9). Rate of re‐operation for MV‐dysfunction was 2.3% versus 2.5% (mitral valve replacement, P=1.0). After propensity matching, patients after MV‐repair still had improved survival at 1, 2, and 5 years (93.4%, 91.6%, 76.9% versus 77.2%, 75.2%, 58.7%, P=0.03). Conclusions Excellent outcomes can be achieved after MV surgery in elderly patients. Long‐term survival is superior after MV‐repair and the re‐operation rate is low. MV‐repair should be the preferred surgical approach in elderly patients.

Complicated infective aortic endocarditis: comparison of different surgical strategies

OBJECTIVES The choice of substitute during aortic valve replacement for infective endocarditis (IE) is still widely debated. We retrospectively reviewed all patients operated for aortic IE and compared groups according to the complexity of IE and substitutes implanted. METHODS From 2000 to 2015, 187 patients were treated using stentless bioprostheses (SBP) as root replacement (n = 30), mechanical prostheses (MP, n = 45) or stented bioprostheses (SP, n = 112) (mean follow-up 4.6 years, survival data 100% complete). RESULTS MP patients were younger (42.5 ± 10.7 vs 57.2 ± 16.9 years [SBP], 59.1 ± 14.1 years [SP], P < 0.01), but rates of intravenous drug use and chronic dialysis were not different. SBP patients more often had root involvement (83.3% vs 33.3% [MP], 25.9% [SP], P < 0.01) and prosthetic valve endocarditis (53.3% vs 6.7% [MP], 12.5% [SP], P < 0.01). In-hospital complications and length of stay were not different. Thirty-day mortality was 13.3% [SBP], 6.7% [MP] and 12.5% [SP] (P = 0.53). Five-year survival tended to be superior in SBP (83.3% vs 77.6% [MP], 67.1% [SP], P = 0.09). In patients with complicated IE (root involvement or prosthetic valve endocarditis, n = 77), SBP had superior long-term survival (86.9% vs 81.3% [MP], 57.2% [SP], PSBP/MP  = 0.07, PSBP/SP = 0.05). No early reinfection (<90 days) occurred in SBP vs 4.4% [MP] and 7.1% [SP] (P = 0.29). Reoperation for late reinfection occurred in 6.7% [SBP] vs 11.1% [MP] and 12.5% [SP] (P = 0.65). Prosthesis failure occurred in 3.3% [SBP] and 1.8% [SP] (P = 0.52). CONCLUSIONS Use of SBP provides favourable outcomes in patients with IE with low rates of reinfection and valve deterioration. It seems to be an optimal device in patients with complex IE.

Inception of the ‘endocarditis team’ is associated with improved survival in patients with infective endocarditis who are managed medically: findings from a before-and-after study

Objective Despite improvements in its management, infective endocarditis (IE) is associated with poor survival. The aim of this study was to evaluate the impact of a multidisciplinary endocarditis team (ET), including a cardiologist, microbiologist and a cardiac surgeon, on the outcome of patients with acute IE according to medical or surgical treatment strategies. Methods We conducted an observational before-and-after study of 196 consecutive patients with definite IE, who were treated at a tertiary reference centre between 2009 and 2015. The study was divided into two periods: period 1, before the formation of the ET (n=101), and period 2, after the formation of the ET (n=95). The role of the ET included regular multidisciplinary team meetings to confirm diagnosis, inform the type and duration of antibiotic therapy and recommend early surgery, when indicated, according to European guidelines. Results The patient demographics and predisposing conditions for IE were comparable between the two study periods. In the time period following the introduction of the ET, there was a reduction in both the time to commencement of IE-specific antibiotic therapy (4.0±4.0 days vs 2.5±3.2 days; P=0.004) and the time from suspected IE to surgery (7.8±7.3 days vs 5.3±4.2 days; P=0.004). A 12-month Kaplan-Meier survival for patients managed medically was 42.9% in the pre-ET period and 66.7% in the post-ET period (P=0.03). The involvement of the ET was a significant independent predictor of 1-year survival in patients managed medically (HR 0.24, 95% CI 0.07 to 0.87; P=0.03). Conclusions A standardised multidisciplinary team approach may lead to earlier diagnosis of IE, more appropriate individualised management strategies, expedited surgery, where indicated, and improved survival in those patients chosen for medical management, supporting the recent change in guidelines to recommend the use of a multidisciplinary team in the care of patients with IE.

Pneumococcal pulmonary valve endocarditis

Pulmonary valve endocarditis is a rare type of infective endocarditis (IE). Streptococcus pneumoniae is a pathogen that is uncommonly associated with IE. A 50 year-old male was referred to us after an incidental echocardiographic finding of a pulmonary valve vegetation. The patient had a recent admission for drainage of a scrotal abscess from which S. pneumoniae was isolated, complicated by hospital acquired pneumonia and pulmonary embolism. Analysis using polymerase chain reaction of the surgically resected mass revealed signs of 16S ribosomal DNA consistent with S. pneumoniae infection. This was an extremely rare case of pneumococcal pulmonary valve IE presenting entirely asymptomatically in the absence of any known risk factors. Learning points: Streptococcus pneumoniae endocarditis can present with very few symptoms or even entirely asymptomatically, as in this case. Pulmonary valve endocarditis can affect healthy patients, even in the absence of any known predisposing risk factors or pre-existing heart conditions. An echocardiogram may be considered following severe infection with sepsis by pneumococci, to screen for vegetations that could evolve silently over the following weeks.

Aortic thrombus causing myocardial infarction after recreational MDMA use

A 20-year-old man presented with a 5-h history of central chest pain radiating to his back and left arm. The ECG showed ST elevation in leads V2 and V3. A trans-thoracic echocardiogram did not show any abnormalities apart from a suspicion of an echogenic structure in the proximal ascending aorta close to the aortic valve. The nature …

Thrombolysis of a prosthetic mitral valve in a 50-day-old child

This case report demonstrates both an implantation of a prosthetic mitral valve in a 50 day-old infant, and also the subsequent successful thrombolysis of an obstructive thrombus in the early postoperative period.

76 Medical management of infective endocarditis by a multidisciplinary endocarditis team’ improves survival: findings from a before-after study

Introduction Despite improvements in its management, infective endocarditis (IE) is associated with poor survival. The aim of this study was to evaluate the impact of a multidisciplinary endocarditis team (ET), including a cardiologist, microbiologist and a cardiac surgeon, on the outcome of patients with acute IE according to medical or surgical treatment strategies. Methods We conducted an observational before-after study of 196 consecutive patients with definite IE, who were treated at a tertiary reference centre between 2009 and 2015. The study was divided into 2 periods: period 1, before the formation of the ET (n=101), and period 2, after the formation of the ET (n=95). The role of the ET included regular multidisciplinary team meetings to confirm diagnosis, inform the type and duration of antibiotic therapy and recommend early surgery, when indicated, according to European guidelines (figure-1). Results The patient demographics and predisposing conditions for IE were comparable between the two study periods (table-1). In the time period following the Introduction of the ET, there was a reduction in both the time to commencement of IE-specific antibiotic therapy (4.0±4.0 days vs 2.5±3.2 days; p=0.004) and the time from suspected IE to surgery (7.8±7.3 days vs 5.3±4.2 days; p=0.004). 12 month Kaplan-Meier survival for patients managed medically was 42.9% in the pre-ET period and 66.7% in the post-ET period (p=0.03) (figure-2). In multivariate Cox regression analysis, the involvement of the ET was a significant independent predictor of 1 year survival in patients managed medically (HR 0.24, 95% CI 0.07–0.87; p=0.03). Abstract 76 Table 1 Demographic, clinical, microbiology and echocardiographic characteristics of patients with definite endocarditis according to study period Abstract 76 Figure 1 Referral pathway and journey of patients with infective endocarditis Abstract 76 Figure 2 Kaplan-Meier survival curves comparing survival between the pre-ET and post-ET time periods in medically managed patients with infective endocarditis Conclusions A standardised multidisciplinary team approach may lead to earlier diagnosis of IE, more appropriate individualised management strategies, expedited surgery, where indicated, and improved survival in those patients chosen for medical management, supporting the recent change in European Society of Cardiology guidelines to recommend the use of a multidisciplinary team in the care of patients with IE.

141 Aortic Root Replacement in Patients with Bicuspid Aortic Valve Disease Does not Increase Operative Risk – A Single Centre Experience

Objective Bicuspid aortic valve disease (BAV) is associated with aortic root dilation (RD), increasing the risk of adverse aortic root events. Current guidelines recommend concomitant root replacement (ARR) in patients undergoing aortic valve replacement (AVR) when the root diameter (ARD) is ≥45 mm. However, ARR is believed to increase surgical risk and adherence to the guidelines is low. We reviewed current practice of surgery for BAV at our centre and compared long-term outcomes of AVR, either isolated or with ARR. Methods Our in-hospital database was explored for patients who were treated for congenital BAV between 2004 and 2015. Patients with concomitant replacement of the ascending aorta and coronary artery bypass grafting (CABG) were left in the group, concomitant non-aortic heart valve procedures and patients with functional BAV were excluded. The remaining 242 patients were divided according to the treatment received, into patients receiving ARR (n = 59) or isolated AVR (n = 183). A sub-analysis of patients with pre-existing RD was performed. Results ARR patients were significantly younger (58.3 ± 14.6 yrs vs. 64.3 ± 12.0 yrs, p < 0.01) and had a significantly higher logistic EuroSCORE (11.3 ± 10.3% vs. 6.1 ± 8.3%, p < 0.01). Mean ARD was 39.5 ± 7.1 mm in ARR vs. 34.5 ± 5.4 mm in AVR (p < 0.01). In the AVR group, 32.2% of patients had an ARD ≥ 40 mm (n = 59), from these, 8.2% (n = 15) had an ARD ≥ 45 mm prior to the procedure. Procedural times were significantly longer in ARR (Bypass time: 110.3 ± 36.2 mins in ARR vs. 78.2 ± 31.0 mins in AVR, p < 0.01), in 8.2% of AVR patients (n = 15) concomitant aortoplasty was performed. Perioperative complications were similar after both procedures, as stroke occurred in 1.7% (n = 1) after ARR and 2.2% (n = 4) after AVR (p = 1.0), dialysis was not necessary in any ARR patient and in 1.1% (n = 2) in AVR (p = 1.0). In ARR, survival at 30 days was 100% vs. 99.5% in AVR (p = 1.0). Median follow-up was 6.1 years. Survival at 5 years was 91.7% in ARR vs. 82.9% in AVR (p = 0.88). During the observational period, 3.4% (n = 2) of the AVR group needed repeat surgery on the ascending aorta due to an increase in ARD. Conclusion Our experience shows, that one-third of patients receiving AVR for BAV is not treated according to current guidelines. Re-operations in this group were due to pre-existent RD. However, ARR does not increase perioperative risk and therefore we recommend ARR as the appropriate treatment in patients with pre-existent RD.

139 Complicated Infective Aortic Endocarditis: Comparison of Different Surgical Strategies

Introduction Infective endocarditis (IE) of the aortic valve complicated by root involvement or an infected prosthesis is a life-threatening condition. While homografts have been promoted previously for treatment, root replacement using stentless bioprostheses (SBP) is an attractive alternative. Still, there is ongoing debate about the optimal substitute in this setting. We compare outcomes of treatment with mechanical prostheses (MP), stented prostheses (SP) and SBP.Abstract 139 Figure 1 Methods Our in-hospital database was explored for patients treated surgically for aortic IE (2000–2015). Valve replacements with homografts were excluded (n = 12). A total of 187 patients received MP (n = 45), SP (n = 112) or SBP (n = 30). All patients with complicated IE (prosthetic valve endocarditis (PVE) or root involvement, n = 77) were included as study cohort. The group was divided according to substitute received (MP (n = 16), SP (n = 36) and SBP (n = 25)). We analysed short-, long-term- and event-free-survival (100% complete). Results SBP and SP patients were older (SBP: 57.8 ± 15.9yrs, MP: 41.7 ± 12.4yrs, SP: 59.7 ± 15.1yrs, p < 0.01). SBP patients suffered more often from PVE (64.0% in SBP vs. 18.7% in MP and 36.1% in SP, p = 0.01), and showed more often root involvement (100% in SBP vs. 93.7% in MP and 83.3% in SP, p = 0.08). MP patients tended to have a higher rate of active intravenous drug use (SBP: 4.0%, MP: 25.0%, SP: 8.3%, p = 0.08). Mean follow-up was 1489 days. Survival was best in the SBP group (87.1% vs. MP: 81.3%, SP: 71.9%) at one year and at five years (SBP: 87.1%, MP: 81.3%, SP: 59.8%, SBP vs. SP p = 0.06). Event-free Survival was 87.1% (SBP), 81.3% (MP), 71.8% (SP) at one year and 74.5% (SBP), 71.8% (MP) and 49.9% (SP) at five years (p = 0.09). Re-operation for re-infection occurred in 8.0% (SBP), 18.7% (MP) and 16.7% (SP) (p = 0.55). No patient experienced valve deterioration. Conclusion Despite a higher pre-operative risk of SBP patients, survival was similar compared to a younger cohort of MP patients and superior to patients with SP. This is most likely an effect of the more radical excision of infected material and should be the preferred surgical option particularly in older patients with complicated IE. In younger patients, the risk of re-infection should be weight against the risk of valve degeneration when the decision is made in favour of MP.