Poor outcomes in methamphetamine-associated cardiomyopathy-a growing health issue in New Zealand.

BACKGROUND: Methamphetamine-associated cardiomyopathy (MAC) is increasingly recognised as a serious consequence of chronic metamphetamine use. Evidence to guide management and prognostication of patients with MAC compared to other cardiomyopathies remain limited. METHODS: Clinical characteristics, in-hospital and post-discharge outcomes were collected in consecutive MAC patients at Middlemore Hospital from 2006-2018, and compared with a 1:1 age-range matched cohort with non-ischaemic cardiomyopathy (NCM). RESULTS: Sixty-two patients (eight females, median age 41 years) with MAC were included. MAC patients were younger than the NCM cohort, and the majority were of indigenous Maori ethnicity. MAC patients had higher peak N-terminal pro B-type natriuretic peptide (NT-proBNP) and lower left ventricular (LV) ejection fraction at presentation. No patients died during index admission. However, there were more MAC patients (10 versus two, P=0.030) with cardiogenic shock at presentation. There were 15 deaths in the MAC patients and seven deaths in the NCM patients during follow-up. MAC patients were at increased mortality risk (HR 2.7, 95% confidence interval 1.1-6.2, P=0.029), and had a trend to more heart failure re-admissions. (HR 1.6, 95% CI 1.0-2.8, P=0.075) compared to NCM patients. Baseline LV end diastolic diameter and failure of improvement in right ventricular systolic function during follow-up were independent predictors of mortality, while failure of improvement in LV ejection fraction predicted heart failure readmission in MAC patients. CONCLUSIONS: MAC patients were more likely to be younger, male, of Maori ethnicity and have a worse prognosis when compared to patients with other non-ischaemic cardiomyopathies.

Valve-in-Valve in a Flail Bioprosthetic Mitral Valve With Endocarditis Using a Novel Embolic Protection Device.

A 79-year-old woman presented in cardiogenic shock with a flail bioprosthetic mitral valve leaflet and Staphylococcus aureus endocarditis. In the absence of other viable options, transfemoral valve-in-valve transcatheter mitral valve replacement was performed with a novel embolic protection device, resulting in trace mitral regurgitation and no neurologic complications. (Level of Difficulty: Advanced.).

Prevalence and impact of scan-related anxiety during coronary CT angiography: A prospective cohort study of 366 patients.

BACKGROUND: Scanxiety, the anxiety/stress associated with an imaging test, has never been evaluated in relation to coronary CT angiography (Coronary CTA). As it could impact heart rate and thereby affect image quality of Coronary CTA, we aimed to evaluate the prevalence, severity, and impact of scanxiety on quality and interpretability of Coronary CTA. METHODS: 366 consecutive patients were prospectively presented with a clinical questionnaire comprising two tests to evaluate their scan-related anxiety: the Impact of Event IES-6 (6 questions, final score 0-24) and a visual stress-scale (1 question, score 1-10). Patient demographics, heart rate and final image quality scored by two readers were recorded. Potential independent correlations were sought between IES-6 scanxiety level and image quality, heart rate variability and demographics, using an ordinal logistic regression model. RESULTS: 344 patients (59.9% men, 57.6 ±â€¯10.7yo) completed the questionnaire. 74.1% (255 patients) reported some scan-related distress, with a mean IES-6 score of 4.1 ±â€¯4.3 (range 0-18). There was no significant difference in terms of age, sex or indications for Coronary CTA between the non-anxious (IES-6 = 0) and the anxious (IES-6>0) patients. There was no significant independent correlation between image quality and IES-6 score (OR = 0.98, p = 0.62), nor between IES-6 score and heart rate variability (effect = -0.005, p = 0.97). CONCLUSION: The prevalence of scan-related anxiety - aka scanxiety - in Coronary CTA patients is high (74.1%) but does not appear to impact image quality and interpretability.

Role of MDCT Imaging in Planning Mitral Valve Intervention.

PURPOSE OF REVIEW: Recent advancements in transcatheter valvular interventions have resulted in a growing demand for advanced cardiac imaging to help guide these procedures. RECENT FINDINGS: Both echocardiography and multi-detector computed tomography have played essential roles in the maturation of transcatheter aortic valve replacement and are now building on these experiences and helping inform the nascent field of transcatheter mitral interventions. Advanced imaging is essential to aid in the diagnosis and determination of the mechanism of mitral regurgitation. In addition, they are integral to annular sizing, determination of the suitability of patient anatomy for specific devices and increasingly important in the determination of the risk of left ventricular outflow tract obstruction and providing appropriate patient-specific fluoroscopic angulation in advance of the procedure.

Fractional flow reserve computed tomography in the evaluation of coronary artery disease.

Amongst patients with suspected obstructive coronary artery disease (CAD), less than a third of patients have obstructive disease on invasive coronary angiography (ICA) and fewer still have flow-limiting obstructive disease as determined by invasive fractional flow reserve (FFR). FFR is a powerful tool in guiding revascularization of flow-limiting lesions which in turn improves clinical outcome in those with haemodynamically significant obstructive disease. However FFR is infrequently performed due to the cost, time and patient discomfort the procedure entails. Further advances in non-invasive imaging has allowed FFR to be derived non-invasively by applying computational fluid dynamic (CFD) modeling to the coronary computed tomography angiography (CCTA) dataset without the need to induce hyperemia or modify the standard CCTA acquisition protocol. FFR derived from CCTA has been shown to have excellent correlation with invasive FFR and remains diagnostically robust in presence of reduced signal-to-noise ratio (SNR), coronary calcification and motion artifact. More recently, new data have emerged evaluating the clinical impact of fractional flow reserve computed tomography (FFRCT) on the assessment and management of patients with stable chest pain. One such study is the Prospective LongitudinAl trial of FFRCT: Outcome and Resource IMpacts (PLATFORM) study which showed an improved patient selection for ICA using CCTA-FFRCT approach by increasing the likelihood of identifying obstructive CAD at ICA amongst those intended for invasive testing. CCTA-FFRCT may therefore serve as efficacious gatekeeper to ICA that enriches the ICA population. The utility of FFRCT has also helped deepened our understanding of CAD. Through CFD modeling, it is now recognized that there are mechanistic forces of wall shear stress (WSS) and axial plaque force acting on coronary plaques. This has created further interest in exploring the possible interplay between these mechanistic forces on the development of coronary plaque and vulnerability of these plaques to rupture.

Coronary lumen volume to myocardial mass ratio in primary microvascular angina.

BACKGROUND: Microvascular angina (MVA) is an incompletely understood clinical entity. Computational analysis of coronary Computed Tomography Angiography (CTA) has shown an association between low coronary lumen volume to myocardial mass (V/M) ratio and lower Fractional Flow Reserve values, independent of plaque measures. We hypothesized that low V/M ratio may be present in patients with MVA. METHODS: A retrospective case-control analysis was performed using patients fulfilling guideline criteria for MVA with controls matched for age, gender, coronary risk factors and atherosclerotic plaque burden. V/M was extracted off site (Heartflow Inc; Redwood City, CA) employing allometric scaling laws that allow the definition of the coronary circulation beyond the epicardium. FFRCT values were calculated in the major epicardial coronary arteries for each group. RESULTS: A total of 30 patients with MVA and 32 matched controls were included in the study. Mean total coronary lumen volume (2302 mm3 ± 109 vs 2978 mm3 ± 134, p < 0.001) and mean myocardial mass (90.4 g ± 13.7 vs 100.4 g ± 20.1, p = 0.029) were lower in MVA patients compared to controls. Mean V/M ratio was significantly lower in MVA compared to controls (25.6 mm3/g ± 5.9 vs 30.0 mm3/g ± 6.5, p = 0.007; c-statistic 0.69). V/M ratio did not differ significantly between subclasses of angina severity (p = 0.747). No difference in mean nadir FFRCT values was found between MVA and control groups in the LAD (0.86 ± 0.07 vs 0.83 ± 0.07, p = 0.154), LCX (0.90 ± 0.05 vs 0.90 ± 0.06, p = 0.240) and RCA (0.90 ± 0.04 vs 0.90 ± 0.03, p = 0.773) vessels. CONCLUSION: Patients with microvascular angina demonstrate a significantly lower coronary CTA-derived coronary volume/myocardial mass ratio than asymptomatic controls.

Fractional flow reserve derived from coronary computed tomography angiography reclassification rate using value distal to lesion compared to lowest value.

INTRODUCTION: A standardised approach to the interpretation of FFRCT data is currently lacking. We evaluated the rate of reclassification of FFRCT positivity using the FFRCT value distal to an anatomical stenoses compared to the lowest FFRCT value. METHOD: Patients who underwent coronary CTA and FFRCT analysis were eligible. FFRCT value of ≤ 0.80 was considered positive. Positive FFRCT distal to stenosis was defined as those with a stenoses of ≥ 25% with an associated FFRCT value of ≤ 0.80 within 2cm distal to the lesion. Outcome data on subsequent invasive coronary angiography (ICA) and coronary revascularisation were collected with a minimum follow-up of 60 days to account for delay between referral for invasive testing and/or revascularisation and receiving the procedure. RESULT: 192 patients (mean age 60.7 ± 10.6 years, 67.5% men) were included. FFRCT was positive for lowest FFRCT value in 55.7% of patients. Positive FFRCT value distal to stenosis was found in 31.3%. The overall reclassification rate of those positive for lowest FFRCT value to negative for FFRCT value distal to stenosis was 43.9% (p < 0.01). The reclassification rates were most pronounced for those with intermediate stenoses - 67% for those with < 50% stenoses, p < 0.01; 49% for 50-69% stenoses, p < 0.01. Amongst those who underwent ICA, the rate of revascularization was significant higher for those with positive FFRCT distal to stenosis compared to those positive for lowest FFRCT value (revascularization/ICA = 0.53 vs 0.44, p < 0.01). CONCLUSION: Using FFRCT values distal to a anatomical stenoses, 44% of patients positive for lowest FFRCT value were reclassified as negative for FFRCT value distal to stenosis. Those who underwent ICA, the rate of revascularisation was higher amongst those with positive FFRCT distal to stenosis compared to those positive for lowest FFRCT value.

CT-Defined Prosthesis-Patient Mismatch Downgrades Frequency and Severity, and Demonstrates No Association With Adverse Outcomes After Transcatheter Aortic Valve Replacement.

OBJECTIVES: This study sought to determine if indexed effective orifice area (EOAi), using left ventricular outflow tract measured from computed tomography (EOAiCT), reclassified prosthesis-patient mismatch (PPM) compared with conventional echocardiogram-defined measurements (EOAiTTE). BACKGROUND: PPM does not predict mortality following transcatheter aortic valve replacement (TAVR). However, it is unknown if the EOAiCT of the left ventricular outflow tract improves risk stratification. METHODS: A total of 765 TAVR patients from the PARTNER II (Placement of Aortic Transcatheter Valves II) trial S3i cohort were evaluated. EOAi was calculated using the continuity equation, and the left ventricular outflow tract area was derived from baseline computed tomography. Traditional echocardiographic categories defined PPM: absent (>0.85 cm2/m2), moderate (≥0.65 and ≤0.85 cm2/m2), or severe (≤0.65 cm2/m2). Correlation of EOAiCT and EOAiTTE to 1-year outcomes was performed. RESULTS: The incidence of PPM was 24% with EOACT compared with 45% with EOAiTTE. Only 6% of PPM was graded severe by EOAiCT compared with 9% by EOAiTTE. EOAiTTE, but not EOAiCT, defined PPM showed association with reduced left ventricular mass regression (p = 0.03 vs. p = 0.52). There was no association between PPM and death or rehospitalization at 1 year with either modality. EOACT was associated with minor stroke at 1 year (log-rank p = 0.04), and EOAiTTE with stroke/transient ischemic attack (log-rank p = 0.030). Furthermore, when subjects with mild or greater paravalvular regurgitation were excluded, the presence of PPM did not show association with any outcome. CONCLUSIONS: EOAiCT downgrades frequency and severity of PPM in patients after TAVR, and was not associated with mortality 1 year after TAVR. EOAiTTE, but not EOAiCT, was associated with less left ventricular mass regression.

Comparison of low-dose coronary artery calcium scoring using low tube current technique and hybrid iterative reconstruction vs. filtered back projection.

INTRODUCTION: We sought to validate whether low dose CACS CT with hybrid IR (HIR) could replace standard dose filtered back projection (FBP). METHOD: We enrolled 100 patients to undergo low dose CACS CT with HIR, in addition to routine full dose FBP. RESULTS: No significant difference between full and low dose CT in Agatston score 138.2±360.6 vs. 137.3±356.4 (p=0.272) or calcium mass score 19±48.3 vs. 18.7±49 (p=0.8), respectively. Bland-Altman analysis showed no systematic bias. Calcium volume difference was statistically significant 57.2±134 vs. 55.1±130.2 (p=0.001). CONCLUSION: Low dose CT for calcium scoring with HIR enables stable CACS Agatston score and calcium mass quantification as compared to full dose FBP.

The not so innocent heart murmur: a 5-year experience.

BACKGROUND: Auckland City Hospital (ACH) established a Heart Murmur Clinic (HMC) with the aim of providing prompt assessment of patients with asymptomatic systolic murmurs. This may lead to early intervention and improved outcomes if significant structural heart disease is detected and reassurance if no significant findings are found. Similar clinics for children have proven beneficial; the benefit of a HMC in an adult population has been difficult to determine. AIM: To review the clinical demographics and echocardiographic information of patients presenting to our HMC, to assess what proportion of significance structural heart disease had and determine the common structural abnormalities in this population. METHODS: This is a retrospective review of patients aged ≥15 years presenting to our HMC between March 2010 and December 2015 with an asymptomatic systolic murmur. Patients with previous cardiac surgery or known congenital or valvular heart disease were excluded. RESULTS: A total of 1221 patients was reviewed over the 5-year period; 980 underwent echocardiography. Significant cardiac disease was detected in 156 patients, with 23 patients requiring surgical intervention over the 5-year period. Significant aortic stenosis (n = 43) and mitral regurgitation (n = 48) were the most common pathologies. Patients > 65 years were more likely to have structural heart disease (16% vs 11%, P < 0.05). CONCLUSION: Establishing a HMC has allowed the screening of a large number of patients who would otherwise have low priority for assessment. We have identified a large proportion with significant structural disease, which has allowed for early surgical intervention when appropriate and may potentially result in improved patient outcomes.

Computed tomography assessment for transcatheter aortic valve in valve implantation: The vancouver approach to predict anatomical risk for coronary obstruction and other considerations.

Valve-in-valve implantation of a transcatheter heart valve into a failed bioprosthetic heart valve has emerged as a treatment alternative to repeat conventional surgery. This requires careful pre-procedural assessment using non-invasive imaging to identify patients at risk for procedure related adverse events, such as ostial coronary occlusion. Herein we report how to comprehensively assess aortic root anatomy using computed tomography prior to transcatheter valve implantation for failed bioprosthetic aortic valves.

The effect of a whole heart motion-correction algorithm on CT image quality and measurement reproducibility in Pre-TAVR aortic annulus evaluation.

BACKGROUND: Motion correction (MC) algorithms have been shown to improve image quality, interpretability and diagnostic accuracy in coronary CT angiography. We sought to determine whether MC extended to the whole heart would demonstrate improved image quality and reproducibility of aortic annular measurements in pre-TAVR CT. MATERIALS AND METHODS: Twenty-two consecutive contrast enhanced CT data sets acquired for pre TAVR evaluation using retrospective ECG synchronization during a single heart beat were retrospectively identified. Image data sets were obtained from raw data acquired at 35% and 75% of the R-R interval using both standard (STD) and motion corrected (MC) reconstruction algorithms. Four data sets (2 STD, 2 MC) per patient were analyzed by 2 independent, blinded readers for aortic annular area, short and long axis, perimeter and average diameter. Image quality was graded using a 5 point Likert score (1 and 2 non diagnostic, 5 excellent). Statistical analysis was performed using Wilcoxon matched paired tests, Bland-Altman (B-A) plots and Lin's concordance coefficient comparing 35% STD to 35% MC, and 75% STD to 75% MC. RESULTS: Eighty-eight datasets were analyzed (44 STD, 44 MC). At 35%, there was a significant improvement in image quality for MC (Likert score 3.3 ± 0.9 STD vs. 3.9 ± 0.7 MC, p < 0.007). While B-A analysis demonstrated narrower interobserver agreement for aortic annular area (bias 0.03 vs 0.02 cm(2), range -0.32 to 0.39 cm(2) vs -0.50 to 0.55 cm(2)), and perimeter (bias 0.3 vs 0.3 mm, range -3.1 to 3.8 mm vs -4.6 to 5.3 mm), this was not statistically significant by concordance correlation coefficient. At 75%, there was no significant difference in image quality (Likert score 3.3 ± 0.9 vs. 3.5 ± 0.76, p = 0.454) or annular measurement agreement intervals. CONCLUSION: Motion correction algorithms may yield significant improvements of image quality in systolic CT data sets of the heart. Further validation studies are required to determine the effect on annular measurements and translation into clinical practice.

Management and Long-Term Outcome of Acute Coronary Syndrome Patients Presenting with Heart Failure in a Contemporary New Zealand Cohort (ANZACS-QI 4).

BACKGROUND: Acute heart failure (HF) associated with an acute coronary syndrome (ACS) predicts adverse outcome. There have been important recent improvements in ACS management. Our aim was to describe the management and outcomes in those with and without HF in a contemporary ACS cohort. METHODS: Consecutive patients presenting with ACS between 2007 and 2011 were enrolled in the All New Zealand Acute Coronary Syndrome Quality Improvement (ANZACS-QI) registry. Outcomes and medication dispensing were obtained using anonymised linkage to national data sets. A summary pharmacotherapy measure of "quadruple therapy" was defined as dispensing of at least one agent from each of the four evidence-based classes - anti-platelet, statin, angiotensin converting enzyme inhibitor/angiotensin receptor blocker and beta blocker. RESULTS: Of 3743 ACS patients 14% had acute HF. Acute heart failure patients were older (69.2±12.6 vs 62.3±12.8 years, p<0.001), less likely to have coronary angiography (66% vs 86%, p<0.001) and revascularisation (46% vs 62%, p<0.001). Immediate post-discharge quadruple therapy was higher for those with than without HF (61% vs 55%, p=0.02) but fell to similar levels by one-year (45% vs 53%, p=0.55). At four years follow-up nearly half of those presenting with ACS and HF had died. After adjustment, HF remained a strong predictor of death within 28 days (OR 2.9, 95%CI 1.5 - 5.5) and beyond 28 days (HR 1.8, 95%CI 1.5 - 2.3). CONCLUSION: Acute heart failure complicating ACS is associated with heightened risk of short-term and long-term mortality. One in three ACS patients with HF did not have coronary angiography and less than half received quadruple therapy a year after presentation.

Clinical Characteristics and Outcomes of Patients with Amphetamine-Associated Cardiomyopathy in South Auckland, New Zealand.

BACKGROUND: Amphetamine-associated cardiomyopathy (AAC) is becoming an increasingly recognised entity. The characteristics and outcomes of these patients are poorly understood. METHODS: Thirty patients admitted with heart failure and echocardiographic evidence of cardiomyopathy between 2005 and 2014 and who had a documented history of amphetamine abuse that was considered an important factor in the causation of their cardiomyopathy were retrospectively identified. RESULTS: Mean age at presentation was 40±10 years with a male predominance (n=25, 83%). The majority were of indigenous Maori ethnicity. At presentation, four patients were in cardiogenic shock. Five patients required intensive care unit (ICU) admission for inotropic support and mechanical ventilation. Fifteen had severe left ventricular (LV) dilation (mean LV end-diastolic dimension 6.8±1.0cm) and all patients had severe LV dysfunction (mean LV ejection fraction 22±8%). Despite optimal heart failure therapy, LV size remained significantly dilated with minimal improvement in LV function. During median follow-up of 18 months, five patients died from end-stage heart failure and 17 had at least one readmission with decompensated heart failure. CONCLUSION: Amphetamine-associated cardiomyopathy was seen predominantly in young indigenous Maori men. They presented with severe cardiomyopathy, often requiring ICU admission. Severe LV dilation and significant LV dysfunction persisted despite treatment and mortality was high.

The diagnostic yield of colonoscopy in patients with isolated abdominal pain.

AIM: Colonoscopy is an overstretched resource and there is no consensus on whether isolated abdominal pain is an appropriate indication for colonoscopy. We evaluated the proportion of patients referred for colonoscopy with isolated abdominal pain and determined the diagnostic yield for this indication. METHODS: All patients registered as having a colonoscopy at Waitemata District Health Board on Endoscribe reporting database between March 2005 and February 2010 were included. Patients were recruited based on the indication for colonoscopy of: abdominal pain, iron deficiency anaemia or overt rectal bleeding. All investigations and electronic clinical documents for patients with abdominal pain were retrieved and patients with concurrent anaemia, rectal bleeding, weight loss, altered bowel habit, abdominal mass, previous abnormal investigations and history of inflammatory bowel disease or bowel malignancy were excluded. The diagnostic yield between the 3 study groups were compared using Chi-squared test, Wilcoxon rank sum test and multiple logistic regression models. RESULTS: Total of 10,052 colonoscopies were performed of which only 2,633 fulfilled our inclusion criteria. The abdominal pain group accounted for 1.2% of colonoscopies performed and had the lowest diagnostic yield of 48.8% (P<0.001). Among those with abdominal pain, significant neoplasia was found in 3.3% and was significantly lower than those with iron deficiency anaemia or overt rectal bleeding groups (P<0.001). When segregated by age, the abdominal pain group continued to have significant less neoplasia (3.8%, P=0.001) among those 50 and older but no difference was found among younger patients. CONCLUSIONS: A small proportion of colonoscopy resources are being used to investigate isolated abdominal pain, which is appropriate given the low diagnostic yield of significant pathology, particularly amongst those less than 50 years old.

Carotid endarterectomy in octogenarians.

AIM: This study compared the postoperative complication rate between patients age 80 or older to those younger than 80 to determine if older patients were associated with higher risk of complication following carotid endarterectomy. METHOD: Patients who received carotid endarterectomy between January 1997 and December 2005 were identified using the New Zealand Vascular Surgical Audit Registry. Patients were recruited into the two predetermined age groups. Baseline demographics and the complication rates between the two groups were analysed and compared using Chi-squared test. Confounding factors were adjusted using logistic regression. RESULTS: 1682 patients were identified, of which 243 patients (14%) were age 80 or older. Younger patients were more likely to be male (P=0.002) and diabetics (P=0.047) and more patients in the older age group were symptomatic from the carotid stenosis (P=0.014). The overall complication rate was 17.2% and there was no significant difference between the two groups (P=0.268). The overall combined postoperative death, TIAs and stroke rate was 3.3%. The cardiac complication rate was low but higher in octogenarians at 4.5% compared to 2.2% (P=0.035). CONCLUSIONS: Older age does not appear to be associated with higher perioperative complications in carotid endarterectomy.