Postdischarge outcome after Takotsubo syndrome compared with patients post-ACS and those without prior CVD: ANZACS-QI 19.

Objective: Takotsubo syndrome (TS) mimics acute coronary syndrome (ACS) but has a distinct pathophysiology. While in-hospital adverse outcomes appear similar to those presenting with an ACS, data on longer term postdischarge risk are conflicting. This study sought to assess the long-term prognosis of patients discharged alive after TS. Methods: The clinical profile and in-hospital and long-term outcomes were prospectively assessed in consecutive patients with TS. Survival in patients with TS was compared with two representative age-matched and gender-matched comparison cohorts: a hospitalised ACS cohort and a community cohort without known cardiovascular disease (CVD). Results: Two hundred and-twenty-five patients with TS (216 women, mean age 63.7±11.8 years) were included. In-hospital mortality was 1.8% and 1.9% for patients with TS and ACS, respectively. Of the 219 patients with TS with postdischarge follow-up, at a mean follow-up of 4.8±3.2 years, there were 19 (8.3%) deaths, 18 of which were from non-cardiac causes. When compared with the cohort without prior CVD, postdischarge patients with TS were at increased mortality risk (HR 2.00, 95% CI 1.26 to 3.17, p=0.003), but mortality in postdischarge patients with ACS was over threefold higher (HR 3.43, 95% CI 2.97 to 3.96, p<0.0001). Conclusions: In-hospital mortality for patients diagnosed with TS and ACS was similar. However, while postdischarge survivors of TS had a long-term survival which was poorer than for a community-based cohort without known CVD, their survival was better than for postdischarge survivors of an ACS event. Late deaths in patients with TS were almost all from non-cardiac causes.

The Significance of Equivocal Exercise Treadmill ECG for Intermediate Risk Chest Pain Assessment - Insight From Coronary CT Angiography Data.

BACKGROUND: Exercise treadmill test (ETT) is commonly the first-line investigation in troponin-negative chest pain patients. Inconclusive results are common and often lead to repeated functional testings. Coronary computed tomographic angiography (CCTA) has excellent negative predictive value for coronary artery disease detection and may play an important role in their diagnostic workup. We aim to analyse ETT and CCTA findings to understand their modern roles in intermediate risk chest pain population with inconclusive ETT. METHODS: Patients who underwent both ETT and CCTA at our institution between August 2011 and February 2013 were retrospectively investigated. The ETTs were blindly reviewed, with equivocal ETTs defined as any indeterminate results not strictly adhering to ACC/AHA guidelines for positive ETT. Baseline demographics, clinical characteristics and investigation results were collated. Follow-up outcome data for subsequent investigations, representations, major cardiac adverse events (MACE) and unexpected revascularisations were also analysed. RESULTS: 346 consecutive patients were identified (age 57±10years, 53% females, body mass index (BMI) 28±4, Dukes Clinical Score 48±30%, mean follow-up 2.1±0.4years). The ETT was positive in 31%, equivocal in 54% and negative in 15%. Obstructive coronary artery disease (CAD) prevalence was 25% (29% males, 13% females). Those with negative ETTs had obstructive CAD in 8%, with no adverse outcomes during follow-up. Obstructive CAD was seen in 20% with "equivocal" ETTs and 29% with "positive" ETTs. In females, obstructive CAD prevalence was low, and similar in those with equivocal or positive ETT (16% and 11% respectively). In males, obstructive CAD was almost 50% in those with positive ETT (p=0.005). CONCLUSIONS: Obstructive CAD was found in one in five "equivocal" ETTs, hence, not all should be considered negative. Obstructive CAD was only found in one in three "positive" ETTs, hence not all should proceed to invasive angiography. CCTA may be an important gatekeeper test in those with low-intermediate pre-test probability of obstructive CAD.

ICare-ACS (Improving Care Processes for Patients With Suspected Acute Coronary Syndrome): A Study of Cross-System Implementation of a National Clinical Pathway.

BACKGROUND: Efforts to safely reduce length of stay for emergency department patients with symptoms suggestive of acute coronary syndrome (ACS) have had mixed success. Few system-wide efforts affecting multiple hospital emergency departments have ever been evaluated. We evaluated the effectiveness of a nationwide implementation of clinical pathways for potential ACS in disparate hospitals. METHODS: This was a multicenter pragmatic stepped-wedge before-and-after trial in 7 New Zealand acute care hospitals with 31 332 patients investigated for suspected ACS with serial troponin measurements. The implementation was a clinical pathway for the assessment of patients with suspected ACS that included a clinical pathway document in paper or electronic format, structured risk stratification, specified time points for electrocardiographic and serial troponin testing within 3 hours of arrival, and directions for combining risk stratification and electrocardiographic and troponin testing in an accelerated diagnostic protocol. Implementation was monitored for >4 months and compared with usual care over the preceding 6 months. The main outcome measure was the odds of discharge within 6 hours of presentation RESULTS: There were 11 529 participants in the preimplementation phase (range, 284-3465) and 19 803 in the postimplementation phase (range, 395-5039). Overall, the mean 6-hour discharge rate increased from 8.3% (range, 2.7%-37.7%) to 18.4% (6.8%-43.8%). The odds of being discharged within 6 hours increased after clinical pathway implementation. The odds ratio was 2.4 (95% confidence interval, 2.3-2.6). In patients without ACS, the median length of hospital stays decreased by 2.9 hours (95% confidence interval, 2.4-3.4). For patients discharged within 6 hours, there was no change in 30-day major adverse cardiac event rates (0.52% versus 0.44%; P=0.96). In these patients, no adverse event occurred when clinical pathways were correctly followed. CONCLUSIONS: Implementation of clinical pathways for suspected ACS reduced the length of stay and increased the proportions of patients safely discharged within 6 hours. CLINICAL TRIAL REGISTRATION: URL: https://www.anzctr.org.au/ (Australian and New Zealand Clinical Trials Registry). Unique identifier: ACTRN12617000381381.

Strain-time curve analysis by speckle tracking echocardiography in cardiac resynchronization therapy: Insight into the pathophysiology of responders vs. non-responders.

BACKGROUND: Patients with non-ischemic heart failure etiology and left bundle branch block (LBBB) show better response to cardiac resynchronization therapy (CRT). While these patients have the most pronounced left ventricular (LV) dyssynchrony, LV dyssynchrony assessment often fails to predict outcome. We hypothesized that patients with favorable outcome from CRT can be identified by a characteristic strain distribution pattern. METHODS: From 313 patients who underwent CRT between 2003 and 2006, we identified 10 patients who were CRT non-responders (no LV end-systolic volume [LVESV] reduction) with non-ischemic cardiomyopathy and LBBB and compared with randomly selected CRT responders (n = 10; LVESV reduction ≥15%). Longitudinal strain (εlong) data were obtained by speckle tracking echocardiography before and after (9 ± 5 months) CRT implantation and standardized segmental εlong-time curves were obtained by averaging individual patients. RESULTS: In responders, ejection fraction (EF) increased from 25 ± 9 to 40 ± 11% (p = 0.002), while in non-responders, EF was unchanged (20 ± 8 to 21 ± 5%, p = 0.57). Global εlong was significantly lower in non-responders at pre CRT (p = 0.02) and only improved in responders (p = 0.04) after CRT. Pre CRT septal εlong -time curves in both groups showed early septal contraction with mid-systolic decrease, while lateral εlong showed early stretch followed by vigorous mid to late contraction. Restoration of contraction synchrony was observed in both groups, though non-responder remained low amplitude of εlong. CONCLUSIONS: CRT non-responders with LBBB and non-ischemic etiology showed a similar improvement of εlong pattern with responders after CRT implantation, while amplitude of εlong remained unchanged. Lower εlong in the non-responders may account for their poor response to CRT.

Role of cardiac magnetic resonance imaging in assessing ischemic and nonischemic cardiomyopathies.

One of the diagnostic challenges in cardiology is the assessment of patients with suspected cardiomyopathies. The traditional approach involves clinical history and examination, followed by echocardiography and invasive angiography. Advances in cardiac MRI enable cardiologists to comprehensively assess both ischemic and nonischemic cardiomyopathies, providing information regarding cardiac anatomy, myocardial and valve functions, as well as tissue characterization.

Cardiac magnetic resonance in hypertrophic cardiomyopathy.

Hypertrophic cardiomyopathy is a complex genetic cardiovascular disorder with substantial variability in phenotypic expression and natural progression. Recent research demonstrates the incremental utility of cardiac magnetic resonance in the diagnosis, therapeutic planning, and prognostication of this disease. The increasing incorporation of multimodality imaging of hypertrophic cardiomyopathy in clinical practice will continue to improve our understanding of the subtle morphologic differences and their prognostic implications.

Role of Transesophageal Echocardiography Compared to Computed Tomography in Evaluation of Pulmonary Vein Ablation for Atrial Fibrillation (ROTEA study).

BACKGROUND: Computed tomography (CT) is the gold standard for assessing pulmonary vein (PV) anatomy and stenosis after ablation for atrial fibrillation (AF), but radiation exposure can be a concern. Transesophageal echocardiography (TEE) provides anatomic and functional assessment of the PVs, although no study has prospectively compared findings on TEE with those on CT. METHODS: The Role of Transesophageal Echocardiography Compared to Computed Tomography in Evaluation of Pulmonary Vein Ablation for Atrial Fibrillation (ROTEA) study was a prospective, single-blinded observational study of patients with paroxysmal or persistent AF undergoing ablation. TEE and CT were performed immediately before and 3 months after AF ablation. The study included 43 patients (84% men; mean age, 56 ± 11 years). RESULTS: In the preprocedural study, TEE identified 98% of PVs with adequate Doppler measurements obtained. After ablation, no moderate or severe PV stenosis was detected on CT, and a 30% to 50% reduction in luminal diameter was seen in 5% of studied veins. Functional PV stenosis by pulsed-wave Doppler was seen in two veins on TEE. PV diameters decreased after ablation by 0.20 ± 0.03 and 0.22 ± 0.03 cm as measured by CT and TEE, respectively (P < .001). However, TEE underestimated PV ostial dimensions compared with CT, especially for the inferior PVs. Severe spontaneous echo contrast and low left atrial appendage emptying velocities, were identified in 10% of patients in sinus rhythm after ablation. CONCLUSIONS: In the ROTEA study, TEE was feasible in assessing PVs before and after ablation, providing both anatomic and functional information that complemented CT. PV ostial dimensions after ablation can be monitored using either modality, although TEE underestimates PV dimensions, especially for the inferior veins.

Clinical utility of multimodality LA imaging: assessment of size, function, and structure.

The reservoir, conduit, and contractile functions of the left atrium are integral to overall cardiac performance. Recent advances in cardiac imaging offer the accurate assessment of LA phasic functions and structure, using techniques such as 3-dimensional echocardiography, color tissue Doppler imaging, and speckle tracking, as well as cardiac computed tomography and magnetic resonance imaging. These new developments are particularly important in view of the increasing use of intervention involving the left atrium. This review article highlights and contrasts the imaging of the size, mechanics, and structure of the left atrium using multiple modalities. The authors discuss recent studies on the clinical applications of the various techniques in disease conditions.

Cardiac magnetic resonance in hypertrophic cardiomyopathy.

Hypertrophic cardiomyopathy is a fascinating and complex disorder with substantial variability in phenotypic expression and natural progression. Recently, there has been substantial research demonstrating incremental utility of cardiac magnetic resonance in the diagnosis and treatment of this disease. With the increasing utilization of multimodality imaging, our understanding of the subtle morphologic differences and their prognostic implications is only going to improve.

Coronary artery anatomy and apical sparing in apical ballooning syndrome: implications for diagnosis and aetiology.

BACKGROUND: Apical ballooning syndrome (ABS) is characterised by transient regional systolic dysfunction involving the left ventricular apex and mid-myocardial segments. The absence of obstructive coronary disease is required in some diagnostic criteria. Some investigators have suggested that a long "wrap-around" left anterior descending (LAD) artery may explain the pattern of regional wall motion abnormalities. METHODS AND RESULTS: We reviewed the coronary angiograms and ventriculograms findings in a prospective ABS cohort of 46 patients (mean age 63+/-13, female 96%). Normal smooth coronary arteries were observed in 54%, with 30% having minor irregularities. Moderate or severe coronary artery lesions were identified in 7 (15%) patients, including 4 with moderate LAD disease. The extent of the LAD artery around the left ventricular apex to the diaphragmatic surface of the heart was scored. This score was compared to 60 consecutive gender-matched control patients without ABS and no observed difference between the two groups (p=0.62). 42% had sparing of LV apical akinesis which was independent of the LAD extent. CONCLUSION: Moderate or severe coronary artery stenosis may co-exist in a small proportion of patients with ABS. Exclusion of these patients will underestimate the true incidence of ABS. The prevalence of "wrap-around" LAD is similar in ABS and non-ABS patients. Apical sparing in ABS is more consistent with aetiological hypotheses implicating LV stunning due to acutely elevated LV wall stress, rather than single or multi-vessel coronary spasm.