Mandie Townsend

A novel mechanism of heart failure with normal ejection fraction

Background: Patients with heart failure and a normal left ventricular ejection fraction have significantly reduced left ventricular long-axis function. This paper proposes an explanation for this apparent paradox and suggests a new mechanism of “diastolic” heart failure. Method: The effect of changes in left ventricular hypertrophy on stroke volume and ejection fraction in non-dilated left ventricles was calculated using the area–length method. Further, the effect of a reduction in long-axis shortening on these parameters was determined. Results: Increasing left ventricular hypertrophy resulted in augmentation of systolic wall thickening and ejection fraction but not stroke volume when long-axis shortening was normal. In the presence of abnormal long-axis function, stroke volume was reduced but ejection fraction was preserved. Conclusion: The model predicts that the normal ejection fraction in patients with heart failure may be explained by the presence of left ventricular hypertrophy. The resulting amplified radial thickening in the setting of reduced long-axis shortening explains the preservation of ejection fraction. The reduced stroke volume in the precompensated state rather than diastolic dysfunction may be the cause of heart failure.

Risk profile and outcomes of aortic valve replacement in octogenarians

AIM To investigate the patient characteristics, relationship between the Logistic EuroSCORE (LES) and the observed outcomes in octogenarians who underwent surgical aortic valve replacement (AVR). METHODS Two hundred and seventy three octogenarians underwent AVR between 1996 and 2008 at Bristol Royal Infirmary. Demographics, acute outcomes, length of hospital stay and mortality were obtained. The LES was calculated to characterize the predicted operative risk. Two groups were defined: LES ≥ 15 (n = 80) and LES < 15 (n = 193). RESULTS In patients with LES ≥ 15, 30 d mortality was 14% (95% CI: 7%-23%) compared with 4% (95% CI: 2%-8%) in the LES < 15 group (P < 0.007). Despite the increase in number of operations from 1996 to 2008, the average LES did not change. Only 5% of patients had prior bypass surgery. The LES identified a low risk quartile of patients with a very low mortality (4%, n = 8, P < 0.007) at 30 d. The overall surgical results for octogenarians were excellent. The low risk group had an excellent outcome and the high risk group had a poor outcome after surgical AVR. CONCLUSION It may be better treated with transcatheter aortic valve implantation.

Streptococcus pneumoniae endocarditis on replacement aortic valve with panopthalmitis and pseudoabscess.

A 63-year-old woman with a previous episode of Streptococcus agalactiae endocarditis requiring a bioprosthetic aortic valve replacement presented with a short history of malaise, a right panopthalmitis with a Roth spot on funduscopy of the left eye and Streptococcus pneumoniae grown from vitreous and aqueous taps as well as blood cultures. She developed first degree heart block and her ECG was suggestive of an aortic root abscess. This gradually resolved over 6 weeks, during which she was treated with intravenous antibiotics. After careful consideration, it is likely that what was thought to be an aortic root abscess was instead an area of perivalvular inflammation.

Improved diagnostic role of CMR in acute coronary syndromes and unobstructed coronary arteries: the importance of time-to-CMR

Background Acute coronary syndrome (ACS) still remains one of the leading causes of mortality and morbidity. In the literature 7-15% of patients with ACS have non obstructive coronary artery disease. In these patients CMR can identify different underlying etiologies, mainly myocarditis, myocardial infarction (MI) with spontaneous recanalization/embolus or Tako-Tsubo cardiomyopathy. However the diagnostic pick-up rate of these aetiologies by CMR is highly variable in the literature and patients are not consistently scanned in the same time window.

Fibroelastomas of the left ventricular outflow tract

Primary cardiac tumours are uncommon and most of them are benign myxomas. Only one-tenth of the tumours are fibroelastomas of the cardiac valves. We report two cases with a longstanding history of valvular heart disease where a diagnosis of fibroelastoma of the left ventricular outflow tract was confirmed by histology.

7 Diagnostic accuracy of 12 lead ECG Q-waves as a marker of myocardial scar: validation with CMR

Background Traditionally, the presence of Q-waves on 12 lead ECG is considered a marker of a large and/or transmural myocardial infarction (MI). Late gadolinium enhancement (LGE) cardiovascular magnetic resonance (CMR) accurately identifies the presence and extent of myocardial infarction and has become the gold standard for the assessment of myocardial viability. Aim To determine the diagnostic accuracy of Q-waves on 12 lead ECG to identify myocardial scarring as compared with CMR. Methods Data was collected on 631 consecutive patients referred for a stress CMR with suspected ischaemic heart disease (April 2013 to Mar 2014). A 12-lead ECG was recorded. Pathological Q-waves – deflection amplitude of >25% of the subsequent R wave, or being >0.04 s (40 ms) in width and >2 mm in amplitude in >1 corresponding lead. A comprehensive CMR protocol was used. Transmural infarction was defined as >50% LGE. Results 498 patients were included (mean age of 64 ± 12 years, 71% males). 290 patients demonstrated MI of whom 157 were transmural and 133 sub-endocardial based on CMR LGE. 126 had pathological Q-waves on 12 lead ECG. The sensitivity, specificity, positive, negative predictive value and accuracy of 12 lead ECG Q-wave as a marker of transmural MI was 36%, 80%, 45%, 73% with moderate overall diagnostic accuracy (66%). The diagnostic accuracy of Q waves as a predictor of previous MI (composite of sub-endocardial and transmural) was 55% (Table 1). Abstract 7 Table 1 Sensitivity, specificity, positive predictive value, negative predictive value and diagnostic accuracy of ECG Q-waves vs LGE myocardial infarction scar Sensitivity (%) Specificity (%) Positive Predictive value (%) Negative Predicitive value (%) Accuracy (%) Q waves vs transmural MI 36.3 79.8 45.3 73.1 66.1 Q waves vs any MI 32.8 85.1 75.4 47.6 54.6 Conclusion Our study demonstrates that the presence of pathological Q-waves on 12 lead ECG is not only a poor marker of myocardial scarring, but also a poor predictor of viability when compared to CMR. In their clinical decision making process, clinicians needs to be aware of the limitation of ECG Q-waves.

127 Early Versus Late CMR in Troponin-Positive Chest Pain with Unobstructed Coronaries

Background Acute coronary syndrome (ACS) is one of the leading causes of morbidity and mortality. Up to 15% of ACS patients are left with a diagnostic dilemma when no significant coronary obstruction is identified. In these patients, CMR can identify different underlying diagnoses including: myocarditis, myocardial infarction (MI) with spontaneous recanalisation/embolus or Tako-Tsubo cardiomyopathy. However, there are discrepancies in the literature on the diagnostic pick-up rate by CMR and patients are not consistently scanned in the same time window. Aim To evaluate the diagnostic role of performing CMR “early” (< 2 weeks from presentation) versus “late” (>2 weeks from presentation) in patients with troponin positive ACS and unobstructed coronaries. Methods In this retrospective observational study, performed at a large cardiothoracic tertiary centre in the South-West of England, data were collected on consecutive patients with troponin positive ACS and unobstructed coronaries, referred for a CMR (September 2011 to July 2014). CMR was performed on a 1.5T scanner (Avanto, Siemens) using a comprehensive protocol that included long- and short-axis cines, T2 weighted STIR and early and late gadolinium enhancement. Each scan was reported by a consultant with >10 yrs CMR experience. Results 204 consecutive patients (mean age 55 yrs) were included in the analysis (51% males). The median time interval between presentation and CMR was 20 days (range 1–150 days). An “early” CMR was performed in 96 patients (median 6 days and range 1–14 days) and 108 patients underwent a “late” CMR scan (median 41 days and range 15–150 days). Overall, CMR identified a diagnosis in 70% of patients, whilst the remaining 30% of patients were classified as normal/unknown diagnosis. An “early” CMR scan significantly improved the diagnostic pick-up rate compared to a “late” CMR scan: 82% vs 54% respectively (p < 0.0001). Myocarditis was the most common diagnosis in “early” CMR (34%) whereas reperfused MI in “late” CMR (26%). Conclusion The diagnostic role of CMR is significantly improved when performed within 2 weeks of acute presentation of troponin positive ACS with unobstructed coronaries. “Early” CMR established a final diagnosis in 82% of a large cohort of patients. In patients with ACS and unobstructed coronary arteries, CMR should be offered within a specified time window, ideally <2 weeks from presentation, in order to increase its diagnostic role and guide appropriate patient management. Abstract 127 Figure 1 Graph to show comparison of diagnosis made in early CMR versus late CMR Abstract 127 Table 1 Demographics table Characteristics Total cohort Early CMR Late CMR P-value Mean age (SD) 55 (17) 55 (17) 57 (17) NS Male sex% 51 54 48 NS Family history of IHD% 6 4 8 NS Diabetes% 12 8.8 16 NS History of smoking% 11 7 16 NS Mean troponin-T ng/L 640 771 496 0.0195 Median interval between acute presentation and CMR in days 20 4 49 <0.0001

92 The Importance of Auditing Procedural Outcomes from Percutaneous Balloon Mitral Valvuloplasty

Introduction Mitral stenosis (MS), as a consequence of rheumatic fever (RF), carries a substantial worldwide morbidity and mortality. Despite the decrease in RF in industrialised countries due to improved antibiotic control, increasing immigration rates mean that RF still represents an important healthcare burden. Percutaneous balloon mitral valvuloplasty (PBMV) is the favoured treatment for MS. Our audit aimed to review recent PBMV practice at University Hospitals Bristol (UHB) and ensure that the results from this large tertiary centre are in line with the European Society of Cardiology (ESC) guidelines. There is no European PBMV audit data published to date. Methods A retrospective audit of PBMV patients from the last 5 years. Data was collected from the CARRDAS database, patient notes, echocardiogram reports and raw data (for missing echocardiographic values). Standards Abstract 92 Table 1 Criteria Target (%) Exceptions Source of evidence 1 Transoesphageal echocardiogram performed before PBMV operation 100 None European Valvular Heart Disease Guidelines 2 Wilkins Score (for suitability of patient for PBMV) calculated before PBMV operation 100 None European Valvular Heart Disease Guidelines 3 Good result of valve widening (with a valve area of greater than 1.5cm2) Greater than 80 None Baumgartner et al., 2009 4 No complication of a pericardial effusion following PBMV operation Greater than 99.5 None Varma et al., 2005 5 No complication of severe mitral regurgitation following PBMV operation Greater than 98 None Varma et al., 2005 Results 22 cases (and 1 repeat procedure) were analysed. A pre-operative transoesphageal echocardiogram (TOE) was performed on 100% patients. Following PBMV, the mean mitral valve area increased significantly by 50% (p < 0.05). The post-procedural peak and mean gradient across the mitral valve were significantly decreased (32% and 50% respectively, p < 0.05). The pulmonary pressure decreased by 16% however this result did not reach significance (Graph 1). The mean increase in valve area was 0.49cm2 however only 56% of post-operative valve areas measured above 1.5cm2, which falls below the ESC target of 80%. In terms of post-operative complications, no patients exhibited severe mitral regurgitation (target <2%). However, the complication rates of pericardial effusion, endocarditis and groin haematoma were higher (Graph 2). Despite the percentage of pericardial effusions appearing high, it is important to note that this represents only 2 cases in a small study population.The Wilkins Score was poorly documented with evidence in only 4% of cases (target 100%). Abstract 92 Figure 1 Abstract 92 Figure 2 Conclusion Comparing the results of this study to ESC guidelines indicates a favourable outcome in this cohort of patients. The completion of pre-operative TOEs and avoidance of severe valve regurgitation following surgery were exemplary. The increase in mean valve area and decrease in peak and mean valve gradients were significant and substantial. However, the Wilkins Score must be calculated and documented to reinforce decision making throughout the PBMV process. Furthermore, the acceptable ESC PBMV complication rates are: pericardial effusion 0.5–10%, severe regurgitation 2–10% and endocarditis 0%. UHB is a tertiary centre with large referral catchment area yet still has a low volume of cases (<5/year on average). Therefore, in light of this limited caseload, it is important to maintain a small team of operators in order to maximise their experience and expertise. Continuous evaluation of the PBMV process is essential due to the minimal number of MS patients presenting each year.

99 5 Year Experience of Tavi Implantation: Patient Characteristics, Morbidity and Mortality

Aims To define the characteristics of a real world population treated with transcatheter aortic valve implantation (TAVI) in a tertiary hospital and to evaluateclinical outcome. This includes in hospital morbidity rates and a comparison of 30 day, 1 year and 2 year mortality rates with those of the UK TAVI registry. We also present 3 year mortality data which to date has not been evaluated from the UK TAVI registry. Methods The Bristol Heart Institute TAVI database was created to record procedural details and outcomes. Data was analysed on 144 consecutive patients undergoing TAVI between January 2008 and March 2013. Results Patient characteristics are shown in Table 1. Peak aortic valve gradient (mean ± SD) was 80.7 ± 24.1mmHg. Of note, the mean age at implantation was 83 ± 6 years, 40.1% had undergone previous cardiac surgery, 65.2 % had a creatinine clearance of < 50 ml/min, 31.2% had a left ventriclular ejection fraction (LVEF) of <50% and at the time of implant 63.2% of patients had a NYHA functional class status of III/IV. Diabetes was present in 17.4%. Procedural characteristics are recorded in Table 2. A variety of access routes were used: femoral 77.71%; subclavian 8.3%; trans apical 13% and trans aortic 0.7% (n = 1). Deployment was successful in 95.8% of patients, with the remainder receiving either a second device implant (2.8%) or conversion to open surgery (1.4%). Immediately post deployment there was ≥ moderate paravalvar AR in 12.3% of patients (vs. 13.6% UK TAVI registry) although this improved to 2.7 % during follow up imaging. Major vascular complication rate was 3.4% (vs. 6.3% UK TAVI registry). In hospital permanent pacemaker rate was 18.7 % (vs. 16.3% UK TAVI registry) and the incidence of stroke was 2.7% (vs. 4.1% UK TAVI registry). Mortality rate (vs. UK TAVI registry data) at 30 days was 6.1% (vs. 7.1%); 1 year was 15.2% (vs. 21.4%) and 2 years was 22.7% (vs. 26.3%). Our 3 year mortality rate is 28.7%. Conclusions Previous studies have shown that significant para prosthetic AR is associated with worse outcome and higher mortality rates. Post implantation paraprosthetic AR is evident in a large proportion of patients (in keeping with previous studies) although with time self expansion of the deviceimproves this. We have shown in this elderly and high risk population that medium term survival is encouraging and favourable when compared with national data. Local auditing of TAVI is important to ensure acceptable morbidity and mortality rates when compared with national ranges and to provide our patients with contemporary information to make an informed decision. Abstract 99 Table 1 Patient characteristics Variable Number (% of total) Male 73 (51) Age (Years) 83 ± 6 COPD 35 (24.3) Cerebrovascular disease (CVA / TIA) 33 (22.3) Previous cardiac surgery 59 (40.1) Creatinine clearance <50ml/min 94 (65.2) LVEF 30-50% 39 (27.0) LVEF < 30% 6 (4.2) NYHA functional class III/IV 91 (63.2) Abstract 99 Table 2 Procedural characteristics and complications Peri/Post implantation Variable Number (% of total) Successful deployment 138 (95.8) Deployment of second TAVI needed 4 (2.8) Conversion to open surgery 2 (1.4) Paravalvular ≥ Mod AR 18 (12.3) New ≥ mod MR 4 (2.7) Major Vascular Complication 5 (3.4) Pericardial effusion needing intervention 1 (0.7) PPM 27 (18.7) CVA 4 (2.7)