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.

Effect of Obstructive Sleep Apnea Treatment on Renal Function in Patients with Cardiovascular Disease.

RATIONALE: Obstructive sleep apnea (OSA) is associated with impaired renal function, but uncertainty exists over whether OSA treatment can influence renal outcomes. OBJECTIVES: To determine the effects of continuous positive airway pressure (CPAP) on renal function in subjects with coexisting OSA and cardiovascular disease. METHODS: This was a substudy of the international SAVE (Sleep Apnea Cardiovascular Endpoints) trial, in which 2,717 patients with moderate to severe OSA and established coronary or cerebrovascular disease were randomized to receive either CPAP plus usual care or usual care alone. Renal function and adverse renal events were compared between the CPAP (n = 102) and usual care (n = 98) groups. Glomerular filtration rate was estimated at randomization and at the end of follow-up, and the urinary albumin-to-creatinine ratio was measured at study exit. MEASUREMENTS AND MAIN RESULTS: In 200 substudy participants (mean age, 64 yr; median, 4% oxygen desaturation index; 20 events/h; mean estimated glomerular filtration rate at baseline, 82 ml/min/1.73 m2), the median (interquartile range) changes in estimated glomerular filtration rate (ml/min/1.73 m2/yr) were -1.64 (-3.45 to -0.740) in the CPAP group and -2.30 (-4.53 to -0.71) in the usual care group (P = 0.21) after a median of 4.4 years. There were no between-group differences in end-of-study urinary albumin-to-creatinine ratio or in the occurrence of serious renal or urinary adverse events during the trial. The level of CPAP adherence did not influence the findings. CONCLUSIONS: CPAP treatment of OSA in patients with cardiovascular disease does not alter renal function or the occurrence of renal adverse events. Clinical trial registered with www.clinicaltrials.gov (NCT00738179).

Correlation between vectorcardiographic measures and cardiac magnetic resonance imaging of the left ventricle in an implantable cardioverter defibrillator population.

BACKGROUND: Measures of vectorcardiographic changes and LV remodelling have been associated with arrhythmic risk. However the correlation between the two modalities is not well characterised. METHODS: We correlated spatial QRS-T angle and ventricular gradient with cardiac MRI derived LV global measures and scar pattern in 66 ICD recipients. RESULTS: Spatial QRS-T angle was significantly larger in patients with ischaemic scar than those without scar (150°±22° vs. 119°±46°, p=0.01). Larger spatial QRS-T angle was also correlated with more depressed LV function, more dilated LV and larger LV mass. Ventricular gradient azimuth was significantly different between patients with no scar, non-ischaemic scar and ischaemic scar (20°±49° vs. 38°±62° vs. 65°±48°, p=0.009), but independent of spatial QRS-T angle and LV structure. CONCLUSIONS: Spatial QRS-T angle and ventricular gradient are partially related to LV structural properties. Further investigation is warranted to examine their comparative and combined prognostic value in risk stratification of ventricular arrhythmias.

Demographic differences in the initiation and maintenance of statins in the first year post ACS in New Zealand: a data linkage study (ANZACS-QI 57).

INTRODUCTION: Prior New Zealand studies suggest that only approximately two-thirds of patients who present with an acute coronary syndrome (ACS) are adequately maintained on a statin post-discharge. This could be due to low initiation and/or poor longer-term adherence. AIM: To identify the pattern and adequacy of statin maintenance following ACS from initial prescription to one-year post-discharge. METHODS: All New Zealand Acute Coronary Syndrome Quality Improvement (ANZACS-QI) registry data for consecutive New Zealand residents (2015-2017) who were hospitalised with ACS and managed with coronary angiography were anonymously linked to national datasets to derive a medication possession ratio (MPR) to assess medication maintenance. An MPR ≥0.8 is considered adequate maintenance and ≥1 is considered optimal. RESULTS: Of the 16,557 patients who survived their ACS, 15,431 (93.2%) were prescribed a statin at discharge and 89.8% were dispensed a statin within three months. 79.8% (13,219/16,557) of patients had an MPR ≥0.8 during the first year, but only 61.0% (10,096/16,557) had optimal dispensing over this period. Regression analysis identified the independent predictors of sub-optimal maintenance over the first year as age <45 years, no prior statin and Maori and Pacific ethnicity. CONCLUSION: After ACS discharge, the gap between prescribing and dispensing rates was small with only minor demographic variation. One in ten patients were not initially dispensed a statin. Although eight in ten patients were adequately maintained, only six in ten had optimal maintenance with clear ethnic and age differences, which may reflect more general disparities in healthcare.

Is cardiomegaly on chest radiograph representative of true cardiomegaly: a cross-sectional observational study comparing cardiac size on chest radiograph to that on echocardiography.

AIMS: To determine whether or not cardiomegaly identified on chest radiograph (CXR) is indicative of true cardiomegaly as determined using echocardiography (echo) as the gold standard tool, and therefore whether or not cardiomegaly on CXR should be investigated further. METHODS: CXR and echocardiogram reports were reviewed for the presence of cardiomegaly in a population following non-ST segment elevation myocardial infarction (NSTEMI). Data was evaluated to determine whether cardiomegaly reported on CXR did indeed represent true cardiomegaly. Exploratory analysis was undertaken to determine whether or not Body Surface Area (BSA) was a significant explanatory variable. RESULTS: Data was collected for 244 patients. Thirty-nine were reported to have cardiomegaly on CXR, 22 of those also had cardiomegaly on echo, giving a true positive rate of 56% and a false positive rate of 44%. Fifty-five were reported to have cardiomegaly on echo, of which 33 (60%) did not have cardiomegaly identified on CXR. Sensitivity of CXR to identify cardiomegaly was 40% and specificity was 91% with a positive predictive value of 56% and negative predictive value of 84%. BSA does not appear to be a significant explanatory variable for the discrepancy between the CXR and echo estimates of cardiomegaly. CONCLUSIONS: In patients following an NSTEMI, the true positive rate of cardiomegaly identified on CXR is not too dissimilar to the false positive rate, thereby suggesting that reporting "cardiomegaly" based on CXR findings is inaccurate and rather reporting should simply focus on the cardiothoracic ratio and defining this as an enlarged cardiac silhouette rather than true cardiomegaly. In clinical practice the data indicates that the number needed to investigate to identify true cardiomegaly on echo is only two, thereby concluding that all patients post-NSTEMI with cardiomegaly on CXR should go on to have an echo, consistent with current national guidelines. As the study population were all post-MI, further study is necessary to evaluate whether this association holds true in a wider population.

Sleep-disordered breathing occurs frequently in stable outpatients with congestive heart failure.

BACKGROUND: Sleep-disordered breathing (SDB) has a potential role in the pathogenesis of congestive heart failure (CHF). High rates of central sleep apnea (CSA) are found in patients with severe CHF, and equal proportions of obstructive sleep apnea (OSA) and CSA in are found CHF patients referred to sleep clinics. The prevalence, type, and severity of SDB in unselected stable outpatients with CHF are unknown. STUDY OBJECTIVES: To determine the frequency and type of SDB in stable CHF outpatients and to examine the relationship between indexes of SDB and impaired cardiac function. PARTICIPANTS: Fifty-three of 87 eligible outpatients (left ventricular ejection fraction [LVEF] < 45%) were predominantly male (77%), with an average age of 60.1 +/- 9.8 years, mean body mass index of 27.9 +/- 5.3 kg/m2, and mean LVEF of 34.0 +/- 8.5% (+/- SD). MEASUREMENTS: Polysomnography, clinical questionnaire, echocardiography, urinary catecholamines, and amino-terminal fragment of pro-brain natriuretic peptide (NT-BNP). RESULTS: SDB (apnea-hypopnea index >10 events/h) was demonstrated in 36 patients (68%) including two subgroups: OSA (n = 28, 53%) and CSA (n = 8, 15%). SDB was associated with atrial fibrillation (0% vs 28%, p = 0.02), more severe oxyhemoglobin desaturation (percentage of time with oxygen saturation < 90%: 0.4% vs 7.9%, p = 0.003), sleep disruption (p = 0.003), and higher urinary noradrenaline levels (p = 0.013) in OSA patients and CSA patients, respectively. Subjective sleepiness (Epworth sleepiness scale, 7.5 vs 8.5; p = 0.11), indexes of impaired cardiac function including Minnesota Living With Heart Failure Questionnaire scores, shuttle walk distance, and NT-BNP levels were not related to the presence of SDB (p > 0.05). CSA patients had lower LVEF (p = 0.0013). CONCLUSIONS: SDB is very common in stable outpatients with CHF, and in our sample OSA predominates. Atrial fibrillation and severe left ventricular impairment increased the likelihood of SDB (particularly CSA), whereas symptom severity, subjective daytime sleepiness, exercise capacity, and NT-BNP levels did not. If specific therapy for SDB such as continuous positive airway pressure can be shown to improve major cardiovascular end points, these results support screening of clinically stable CHF patients.