Alcohol septal ablation for hypertrophic obstructive cardiomyopathy: The Auckland experience

Interventional Cardiology 448 A COMPARISON OF CLINICAL OUTCOMES IN STEMI PATIENTS TREATED WITH PRIMARY ANGIOPLASTY WITH AND WITHOUT POST STENT BALLOON DILATATION B. Ko, A. Hutchison, S. Healy, A. Nasis, J.M. Zhang, J. Cameron, I. Meredith, Y. Malaiapan Monash Cardiovascular Research Centre, MonashHEART and Monash University Department of Medicine (MMC), Melbourne, Australia Background: Post dilatation after stent implantation is performed to ensure stent apposition and full expansion. In primary angioplasty, stent size is commonly underestimated, yet balloon dilatation may be associated with distal embolisation and microvascular dysfunction. Methods: STEMI patients who did not undergo post stent balloon dilatation (PSBD) were identified on database. Angiographic and clinical outcomes were assessed. An age, gender and vessel-matched cohort was generated for comparison. Results: 353 patients were admitted with STEMI between 1st December 2007 and 31st December 2008, 22 patients (77% male, median age 67) did not undergo PSBD. Reasons include reperfusion injury post stent requiring resuscitation (3), microvascular dysfunction with slow flow after stenting (3), stent proximity to major side branch (1) and physicians discretion (15). In both the non-PSBD and its matched cohort, the LAD (8), LCX (5), RCA (8) SVG (1) were stented, lesion complexity was C (12), B2 (8) and B1 (2). Average largest balloon diameter was 3.17 mm and 3.27 mm respectively. Average pre stent TIMI/MPG grade were 0.5/0.5 and 0.7/0.6. Average post stent TIMI/MPG were 2.9/2.7 and 2.9/2.6. Angiographic perfusion score was equivalent (6.7) in both groups. At median 9 months follow up, each group had one mortality. Acute myocardial infarction occurred in 0 and 1 patient, catheterisation repeated in 2 and 6 patients, with 0 and 2 patients requiring further percutaneous coronary intervention for instent restenosis in the non-PSBD and its PSBD cohort respectively. Conclusion: The majority of patients in our centre undergo PSBD in primary angioplasty for STEMI. The factors which have resulted in no PSBD are slow flow, reperfusion injury and physicians discretion. Angiographic and short-term clinical outcomes appear to be equivalent in this small cohort. However larger numbers and longer follow-up is required. doi:10.1016/j.hlc.2009.05.494

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449 DEVELOPMENT OF A RISK ADJUSTMENT MODEL FOR LESION SUCCESS IN PCI AND ITS APPLICATION TO SEQUENTIAL PERFORMANCE MONITORING J. Cameron, J. Rivers, I. Smith St Andrew’s Medical Institute, Brisbane, Queensland, Australia Background: Clinical application of statistical process control (SPC) based performance monitoring improves when risk adjustment (RA) is incorporated to account for common cause variation. This project describes the development of a RA model for estimating the probability of failure to re-establish satisfactory flow in the target lesion in coronary angioplasty (lesion failure). Use of the RA model in an SPC application was evaluated. Methods: Prospectively collected data for 3135 PCI procedures involving 4634 lesions were analysed to identify factors predictive of lesion failure. A Bayesian RA model was then built using these factors. RA model performance was evaluated using a cross validation method with the outcome of each set of training and test data evaluated for discrimination and calibration using the area under the receiver operating characteristic curve (AUC) and the Hosmer-Lemeshow “C”-statistic. Cumulative SUM, Cumulative Expected minus Observed and Funnel Plots were constructed using the RA model and subjectively evaluated. Results: Factors identified as being statistically related to lesion failure included the lesion risk class (p < 0.001), occlusion type (p < 0.001), patient age (p = 0.006), unstable angina (p = 0.003) and presence of at least one major cardiac risk factor (p = 0.01). Cross-validation analysis confirmed acceptable performance of the model (median AUC ∼ 0.87, median “C” ∼ 11.4). Alarm signals arising during SPC monitoring were improved through incorporation of the RA model. Conclusion: Application of the RA model to SPC monitoring for lesion failure markedly improved the utility of SPC monitoring for group and individual clinical performance. doi:10.1016/j.hlc.2009.05.495 450 ALCOHOL SEPTAL ABLATION FOR HYPERTROPHIC OBSTRUCTIVE CARDIOMYOPATHY: THE AUCKLAND EXPERIENCE M. Ratnayake, R. Garg, S. Greaves, I. Gerber, M. Webster Greenlane Cardiovascular Service, Auckland City Hospital, New Zealand Background: Alcohol septal ablation (ASA) has been shown to successfully relieve left ventricular outflow tract (LVOT) obstruction and improve symptoms in hypertrophic obstructive cardiomyopathy (HOCM). This study reviewed ASA procedures performed in Auckland. Methods: A retrospective chart review of the medical records of patients who underwent ASA from July 1999 to July 2006 was undertaken.

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Heart, Lung and Circulation 2009;18S:S1–S286

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Heart, Lung and Circulation 2009;18S:S1–S286

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Results: 24 patients (17 females and 7 males) underwent an attempt at ASA. Patients were aged 16–88 years with a median of 64 years. Three had had previous surgical myectomy 1–13 years before. None had previous ASA. Most (82%) had NYHA class 3 or 4 symptoms pre-procedure. Only one had pre-procedure syncope. Intra-coronary alcohol injection was echo-guided, using Levovist or agitated blood/ saline for contrast injection. 1.5–3.0 ml of alcohol were injected. Peri- and post-procedural complications were coronary dissection requiring surgery (1), VT/VF arrest (2), cardiac tamponade (1) and heart block requiring a permanent pacemaker (5). Most (84%) had a marked improvement in symptoms post-procedure to NYHA class 1 or 2, associated with reduced LVOT obstruction. Conclusion: ASA improves symptoms in selected patients with hypertrophic cardiomyopathy.

Conclusion: A rapid 1 h commencement of TR BandTM weaning and removal following diagnostic cardiac catheterization from the radial approach appears to be safe. It shortens the overall device removal time and may shorten hospital stay in day-case procedures. doi:10.1016/j.hlc.2009.05.497 452 FIELD 12 LEAD ECG AND ED ACTIVATION OF THE INFARCT TEAM IN STEMI IMPROVES DOOR TO BALLOON TIMES: AN UPDATE OF THE MONASHHEART ACUTE MYOCARDIAL INFARCTION (MON-AMI) 12 LEAD PROJECT A. Hutchison 1 , Y. Malaiapan 1 , B. Barger 2 , G. Braitberg 3 , J.D. Cameron 1 , I.T. Meredith 1 1 Monash

doi:10.1016/j.hlc.2009.05.496 451 AN OBJECTIVE APPROACH TO HAEMOSTASIS FOLLOWING TRANS-RADIAL CARDIAC CATHETERIZATION Chris Carrington, Rose Mann, Seif El-Jack Cardiovascular Unit, Department of Cardiology, North Shore Hospital, Auckland, New Zealand Introduction: Transradial cardiac catheterization is increasingly gaining grounds as an alternative to a femoral approach. Haemostasis post procedure is achieved by external pressure application using various devices and techniques, TR BandTM being one. There is no standardized protocol for the application and cessation of sustained pressure to achieve adequate haemostasis. Objective: To assess the safety and feasibility of a more rapid (1 h) initiation of TR BandTM removal ([time to wean] TTW1) compared to a recommended 2 h protocol in a controlled prospective study (TTW2). Methods: Consecutive outpatients undergoing diagnostic cardiac catheterization via the radial approach were recruited. Results: 100 patients were recruited into the rapid TTW1 protocol; these were compared to a random cohort of 25 patients who underwent the conventional 2 h to wean approach (TTW2). The mean age was 72 with a mean BMI 29.1 kg/m2 ; 51.2% had hypertension, the mean platelet count was 236.9 and 8.8% were on warfarin. The median times to wean were 60 min (mean 67.75) for TTW1 and 120 min (mean 129.6) for TTW2 groups respectively. Delays in the weaning process due to continued ooze occurred in 17% of TTW1 group and 4% of the TTW2 group (p = 0.181). The total time however from sheath removal to TR BandTM removal was significantly shorter in the TTW1 group compared to TTW2 (median of 120 min {mean 127.43} vs. 180 min {mean 187.2}, p < 0.001). Significant haematoma (>5 cm) occurred in 1% of the TTW1 group compared to none in TTW2, but this was not statistically significant. No other complications occurred in either group.

Cardiovascular Research Centre, MonashHEART, Monash University Department of Medicine (MMC), Monash University, Melbourne, Australia 2 Ambulance Victoria, Melbourne, Australia 3 Southern Health Emergency, Southern Health, Melbourne, Australia Purpose: To investigate the effect on door to balloon times (D2BT) of field 12 lead ECG to triage ST elevation myocardial infarction (STEMI) and emergency department (ED) activation of the infarct team. Methods and results: We performed a prospective interventional study involving 425 patients undergoing primary PCI (PPCI) at a single tertiary referral institution. The D2BT of all patients (n = 134) who underwent PPCI following field ECG and ED activation of the infarct team (MonAMI group) was compared to a contemporary group of 169 patients undergoing PPCI but not receiving field triage (Non-MonAMI group) and 122 consecutive patients who underwent PPCI prior to initiation of field triage and ED infarct team activation (Pre-MonAMI group). The median D2BT in the MonAMI group was 56 min compared to 103 min in the Non-MonAMI group and 101.3 min in the Pre-MonAMI group (p < 0.001). This was driven by a reduction in the median door-to-catheter laboratory time: 28 min (MonAMI group) versus 70 min and 68.3 min (Nonand Pre-MonAMI, respectively; p < 0.001). The median catheter laboratory-to-balloon time remained unchanged (26 min MonAMI group, 29 min Non-MonAMI and PreMonAMI groups p = 0.12). The proportion of patients who achieved a D2BT of ≤90 min increased from 39% in the Pre-MonAMI, 40% in the Non-MonAMI group to 93% in the MonAMI group (p < 0.001). Conclusions: The performance of field 12 lead ECG triage and pre hospital activation of the infarct team significantly improves D2BT and results in a greater proportion of patients achieving guideline recommendations. doi:10.1016/j.hlc.2009.05.498