Neha Sekhri

How effective are rapid access chest pain clinics? Prognosis of incident angina and non-cardiac chest pain in 8762 consecutive patients

Objective: To determine whether rapid access chest pain clinics are clinically effective by comparison of coronary event rates in patients diagnosed with angina with rates in patients diagnosed with non-cardiac chest pain and the general population. Design: Multicentre cohort study of consecutive patients with chest pain attending the rapid access chest pain clinics (RACPCs) of six hospitals in England. Participants: 8762 patients diagnosed with either non-cardiac chest pain (n = 6396) or incident angina without prior myocardial infarction (n = 2366) at first cardiological assessment, followed up for a median of 2.57 (interquartile range 1.96–4.15) years. Main outcome measures: Primary end point—death due to coronary heart disease (International Classification of Diseases (ICD)10 I20–I25) or acute coronary syndrome (non-fatal myocardial infarction (ICD10 I21–I23), hospital admission with unstable angina (I24.0, I24.8, I24.9)). Secondary end points—all-cause mortality (ICD I20), cardiovascular death (ICD10 I00–I99), or non-fatal myocardial infarction or non-fatal stroke (I60–I69). Results: The cumulative probability of the primary end point in patients diagnosed with angina was 16.52% (95% confidence interval (CI) 14.88% to 18.32%) after 3 years compared with 2.73% (95% CI 2.29% to 3.25%) in patients with non-cardiac chest pain. Coronary standardised mortality ratios for men and women with angina aged <65 years were 3.52 (95% CI 1.98 to 5.07) and 4.39 (95% CI 1.14 to 7.64). Of the 599 patients who had the primary end point, 194 (32.4%) had been diagnosed with non-cardiac chest pain. These patients were younger, less likely to have typical symptoms, more likely to be south Asian and more likely to have a normal resting electrocardiogram than patients with angina who had the primary end point. Conclusion: RACPCs are successful in identifying patients with incident angina who are at high coronary risk, but there is a need to reduce misdiagnosis and improve outcomes in patients diagnosed with non-cardiac chest pain who accounted for nearly one third of cardiac events during follow-up.

Acute myocarditis presenting as acute coronary syndrome: role of early cardiac magnetic resonance in its diagnosis

Background In patients presenting with acute cardiac symptoms, abnormal ECG and raised troponin, myocarditis may be suspected after normal angiography. Aims To analyse cardiac magnetic resonance (CMR) findings in patients with a provisional diagnosis of acute coronary syndrome (ACS) in whom acute myocarditis was subsequently considered more likely. Methods and results 79 patients referred for CMR following an admission with presumed ACS and raised serum troponin in whom no culprit lesion was detected were studied. 13% had unrecognised myocardial infarction and 6% takotsubo cardiomyopathy. The remainder (81%) were diagnosed with myocarditis. Mean age was 45±15 years and 70% were male. Left ventricular ejection fraction (EF) was 58±10%; myocardial oedema was detected in 58%. A myocarditic pattern of late gadolinium enhancement (LGE) was detected in 92%. Abnormalities were detected more frequently in scans performed within 2 weeks of symptom onset: oedema in 81% vs 11% (p<0.0005), and LGE in 100% vs 76% (p<0.005). In 20 patients with both an acute (<2 weeks) and convalescent scan (>3 weeks), oedema decreased from 84% to 39% (p<0.01) and LGE from 5.6 to 3.0 segments (p=0.005). Three patients presented with sustained ventricular tachycardia, another died suddenly 4 days after admission and one resuscitated 7 weeks following presentation. All 5 patients had preserved EF. Conclusions Our study emphasises the importance of access to CMR for heart attack centres. If myocarditis is suspected, CMR scanning should be performed within 14 days. Myocarditis should not be regarded as benign, even when EF is preserved.

Inequity of access to investigation and effect on clinical outcomes: prognostic study of coronary angiography for suspected stable angina pectoris

Objectives To determine whether coronary angiography for suspected stable angina pectoris is underused in older patients, women, south Asian patients, and those from socioeconomically deprived areas, and, if it is, whether this is associated with higher coronary event rates. Design Multicentre cohort with five year follow-up. Setting Six ambulatory care clinics in England. Participants 1375 consecutive patients in whom coronary angiography was individually rated as appropriate with the Rand consensus method. Main outcome measures Receipt of angiography (420 procedures); coronary mortality and acute coronary syndrome events. Results In a multivariable analysis, angiography was less likely to be performed in patients aged over 64 compared with those aged under 50 (hazard ratio 0.60, 95% confidence interval 0.38 to 0.96), women compared with men (0.42, 0.35 to 0.50), south Asians compared with white people (0.48, 0.34 to 0.67), and patients in the most deprived fifth compared with the other four fifths (0.66, 0.40 to 1.08). Not undergoing angiography when it was deemed appropriate was associated with higher rates of coronary event. Conclusions At an early stage after presentation with suspected angina, coronary angiography is underused in older people, women, south Asians, and people from deprived areas. Not receiving appropriate angiography was associated with a higher risk of coronary events in all groups. Interventions based on clinical guidance that supports individualised management decisions might improve access and outcomes.

Incremental prognostic value of the exercise electrocardiogram in the initial assessment of patients with suspected angina: cohort study

Objective To determine whether resting and exercise electrocardiograms (ECGs) provide prognostic value that is incremental to that obtained from the clinical history in ambulatory patients with suspected angina attending chest pain clinics. Design Multicentre cohort study. Setting Rapid access chest pain clinics of six hospitals in England. Participants 8176 consecutive patients with suspected angina and no previous diagnosis of coronary artery disease, all of whom had a resting ECG recorded. 4848 patients with a summary exercise ECG result recorded (positive, negative, equivocal for ischaemia) comprised the summary ECG subset of whom 1422 with more detailed exercise ECG data recorded comprised the detailed ECG subset. Main outcome measure Composite of death due to coronary heart disease or non-fatal acute coronary syndrome during median follow-up of 2.46 years. Results Receiver operating characteristics curves for the basic clinical assessment model alone and with the results of resting ECGs were superimposed with little difference in the C statistic. With the exercise ECGs the C statistic in the summary ECG subset increased from 0.70 (95% confidence interval 0.68 to 0.73) to 0.74 (0.71 to 0.76) and in the detailed ECG subset from 0.74 (0.70 to 0.79) to 0.78 (0.74 to 0.82). However, risk stratified cumulative probabilities of the primary end point at one year and six years for all three prognostic indices (clinical assessment only; clinical assessment plus resting ECG; clinical assessment plus resting ECG plus exercise ECG) showed only small differences at all time points and at all levels of risk. Conclusion In ambulatory patients with suspected angina, basic clinical assessment encompasses nearly all the prognostic value of resting ECGs and most of the prognostic value of exercise ECGs. The limited incremental value of these widely applied tests emphasises the need for more effective methods of risk stratification in this group of patients.

Presentation of stable angina pectoris among women and South Asian people

Background: There is speculation that women and South Asian people are more likely than men and white people to report atypical angina and that they are less likely to undergo invasive management of angina. We sought to determine whether atypical symptoms of angina pectoris in women and South Asians impacted clinically important outcomes and clinical management. Methods: We prospectively identified 2189 South Asian people and 5605 white people with recent-onset chest pain at 6 chest-pain clinics in the United Kingdom. We documented hospital admissions for acute coronary syndromes, coronary deaths as well as coronary angiography and revascularization procedures. Results: Atypical chest pain was reported by more women than men (56.5% vs 54.5%, p < 0.054) and by more South Asian patients than white patients (59.9% vs 52.5%, p < 0.001). Typical symptoms were associated with coronary death or acute coronary syndromes among women (hazard ratio [HR] 2.30, 95% CI 1.70–3.11, p < 0.001) but not among men (HR 1.23, 95% CI 0.96–1.57, p = 0.10). Typical symptoms were associated with coronary outcomes in both South Asian and white patients. Among those with typical symptoms, women (HR 0.76, 95% CI 0.63–0.92, p = 0.004) and South Asian patients (HR 0.52, 95% CI 0.41–0.67, p < 0.001) were less likely than men and white patients to receive angiography. Interpretation: Compared to those with atypical chest pain, women and South Asian patients with typical pain had worse clinical outcomes. However, sex and ethnic background did not explain differences in the use of invasive procedures.

Case fatality rates for South Asian and Caucasian patients show no difference 2.5 years after percutaneous coronary intervention

Objective To compare short and medium-term prognosis in South Asian and Caucasian patients undergoing percutaneous coronary intervention (PCI) to determine if there are ethnic differences in case death rates. Design Retrospective cohort study. Setting A cardiology referral centre in east London. Patients 9771 patients who underwent PCI from October 2003 to December 2007 of whom 7966 (81.5%) were Caucasian and 1805 (18.5%) were South Asian. Main outcome measures In-hospital major adverse cardiac events (MACE; death, myocardial infarction, stroke and target vessel revascularisation), subsequent revascularisation rates (PCI and coronary artery bypass grafting; CABG) and all-cause mortality during a median follow-up of 2.5 years (range 1.5–3.6 years). Results South Asian patients were younger than Caucasian patients (59.69±0.27 vs 64.69±0.13 years, p<0.0001), and more burdened by cardiovascular risk factors, particularly type II diabetes mellitus (45.9%±1.2% vs 15.7%±0.4%, p<0.0001). The in-hospital rates of MACE were similar for South Asians and Caucasians (3.5% vs 2.8%, p=0.40). South Asians had higher rates of clinically driven PCI for restenosis and subsequent CABG, although Kaplan–Meier estimates of all-cause mortality showed no significant differences; this was regardless of whether PCI was performed post-acute coronary syndrome or as an elective procedure. The adjusted hazard of death for South Asians compared with Caucasians was 1.00 (95% CI 0.81 to 1.23). Conclusion In this large PCI cohort, the in-hospital and longer-term mortality of South Asians appeared no worse than that of Caucasians. South Asians had higher rates of restenosis and CABG during follow-up. Data suggest that the excess coronary mortality for South Asians compared with Caucasians is not explained by differences in case-fatality rates.

Interaction between arrival time and thrombolytic treatment in determining early outcome of acute myocardial infarction

Background: Shortening prehospital delay has been identified as an important means of improving responses to reperfusion treatment. If this increases the risk profile of the population delivered to hospital, it may paradoxically cause a deterioration in hospital mortality. Objective: To examine the interaction between arrival time (time from onset of chest pain to arrival at hospital) and thrombolytic treatment in determining the early outcome of acute myocardial infarction. Methods: Prospective cohort study of 1723 patients with acute myocardial infarction who were potentially eligible for thrombolytic treatment (ST elevation on ECG; arrival time ≤ 12 hours). Results: All patients were eligible for thrombolysis but only 1098 (80%) received it. Patients who did not receive thrombolytic treatment were older (66 (58–73) v 61 (53–70) years, p < 0.001), more commonly female (32.1% v 24.8%, p < 0.01), and had higher frequencies of previous infarction (28.6% v 15.6%, p < 0.001) and left ventricular failure (37.5% v 26.9%, p < 0.01) than patients who received thrombolytic treatment. For the group as a whole, 30 day mortality was 11.7% and was unaffected by arrival time, but in patients who did not receive thrombolysis an arrival time of ≤ 6 hours was associated with significantly higher 30 day mortality than an arrival time of 6–12 hours (24.3% v 2.6%, p = 0.002). Conversely, in patients who did receive thrombolysis an arrival time of ≤ 6 hours was associated with a lower 30 day mortality than an arrival time of 6–12 hours (8.5% v 14.5%, p < 0.02). Conclusions: Shortening prehospital delay in acute myocardial infarction will tend to increase the risk profile of patients presenting to emergency departments. The data presented here indicate that this may increase hospital mortality if underutilisation of thrombolytic treatment among high risk groups is not diminished.

Effect of diabetes on serum potassium concentrations in acute coronary syndromes

Objectives: To compare serum potassium concentrations in diabetic and non-diabetic patients in the early phase of acute coronary syndromes. Background: Acute phase hypokalaemia occurs in response to adrenergic activation, which stimulates membrane bound sodium-potassium-ATPase and drives potassium into the cells. It is not known whether the hypokalaemia is attenuated in patients with diabetes because of the high prevalence of sympathetic nerve dysfunction. Methods: Prospective cohort study of 2428 patients presenting with acute coronary syndromes. Patients were stratified by duration of chest pain, diabetic status, and pretreatment with β blockers. Results: The mean (SD) serum potassium concentration was significantly higher in diabetic than in non-diabetic patients (4.3 (0.5) v 4.1 (0.5) mmol/l, p < 0.0001). Multivariate analysis identified diabetes as an independent predictor of a serum potassium concentration in the upper half of the distribution (odds ratio 1.66, 95% confidence interval 1.38 to 2.00). In patients presenting within 6 hours of symptom onset, there was a progressive increase in plasma potassium concentrations from 4.08 (0.46) mmol/l in patients presenting within 2 hours, to 4.20 (0.47) mmol/l in patients presenting between 2–4 hours, to 4.24 (0.52) mmol/l in patients presenting between 4–6 hours (p = 0.0007). This pattern of increasing serum potassium concentration with duration of chest pain was attenuated in patients with diabetes, particularly those with unstable angina. Similar attenuation occurred in patients pretreated with β blockers. Conclusion: In acute coronary syndromes, patients with diabetes have significantly higher serum potassium concentrations and do not exhibit the early dip seen in non-diabetics. This may reflect sympathetic nerve dysfunction that commonly complicates diabetes.

Limited Clinical Utility of Holter Monitoring in Patients with Palpitations or Altered Consciousness: Analysis of 8973 Recordings in 7394 Patients

Aims: To determine the clinical utility of 24 hour Holter monitoring by measuring the frequency of candidate arrhythmias recorded during the investigation of palpitations and altered consciousness.

135 Novel Hybrid Positron Emission Tomography - Magnetic Resonance (PET-MR) Multi-modality Inflammatory Imaging has Improved Diagnostic Accuracy for Detecting Cardiac Sarcoidosis

Background Cardiac sarcoidosis (CS) is associated with poor outcomes, but detection remains difficult.Few studies evaluate 18-fluorodeoxyglucose positron emission tomography (PET) and cardiac magnetic resonance imaging (MRI) for CS diagnosis. None examine a novel hybrid PET-MR approach. We sought to examine the diagnostic accuracy of hybrid PET-MR imaging for CS detection. Methods 51 consecutive patients with biopsy-proven or clinically suspected CS (age 48 ± 13 years, 32% males) underwent hybrid PET-MR imaging. 18-FDG tracer uptake and late gadolinium enhancement (LGE) were qualitatively assessed on a binary scale and quantitatively by measuring standardised uptake value (SUV) and % LGE detected in each myocardial segment. Sensitivity and specificity of PET-MR for CS diagnosis was calculated. Inter-modality agreement was performed by the Cohen κ method. Coefficient of variance (COV) was performed to determine whether SUV quantification analysis discriminated between CS presence and absence. Results 37 (73%) of the patients had confirmed sarcoidosis; 46% were histologically proven and 59% had cardiac involvement according to JMHW guidelines. FDG uptake on PET-MR was equivalent to PET-CT (p < 0.001), confirming that simultaneous hybrid PET-MR is feasible. When considered in isolation, sensitivity of PET and MR at detecting abnormalities was 0.65 and 0.6, respectively. In contrast, hybrid imaging had improved sensitivity of 0.89 in detecting probable cardiac sarcoidosis with specificity, positive and negative predictive values of 0.42, 0.8 and 0.6, respectively. Sensitivity for detecting confirmed CS using hybrid PET-MR was 100%. Notably, there was poor inter-modality agreement between the location of increased SUV and LGE (k = 0.021). This may reflect the natural history of CS with progression from inflammation to scar and also account for the sensitivity of hybrid imaging. Coefficient of variance analysis of SUV uptake suggested that a COV above 25% predicted CS. Conclusion This is the first study to describe the feasibility and improved diagnostic accuracy of novel hybrid cardiac PET-MR imaging in CS. This technique may allow for more accurate and earlier diagnoses and may also allow titration of therapy according to disease activity.