CARDIOVASCULAR JOURNAL OF AFRICA • Volume 33, No 3, May/June 2022 140 AFRICA and multivariable regression analyses to measure the association between risk factors and outcomes. A p-value < 0.05 was interpreted as statistically significant. Results As demonstrated in the study flow (Fig. 1), 214 patients presented to New Somerset Hospital between 1 January and 31 December 2016 with a suspected diagnosis of ACS. Of these, 174 fulfilled the diagnostic criteria for ACS. Included in the analysis are 48 (27.5%) patients with STEMI, 43 (24.7%) with NSTEMI and 83 (47.7%) with UAP. As shown in Table 1, the study population had a male preponderance (59.2%) and a median age of 59.5 (IQR 50–68) years. Patients with STEMI (55 years) were younger than those presenting with NSTEMI (63 years) and UAP (60 years, p = 0.022). The majority of the STEMI group were men (77.1%), while NSTEMI and UAP were equally preponderant among both genders. A high prevalence of traditional risk factors for coronary artery disease was observed in the overall study cohort (systemic hypertension 67.8%, smoking 48.3%, diabetes mellitus 33.9%, dyslipidaemia 28.7%). Of these, most patients (64.2%) had at least two risk factors for coronary artery disease. Patients with STEMI were more likely to have a smoking history than those with NSTEMI or UAP (70.8 vs 34.9 vs 42.2%, p < 0.001). Almost a third of all patients (30.5%) had a prior diagnosis of coronary artery disease. Two-thirds of STEMI patients (62.5%) reported non-adherence to their chronic medication prior to presentation. This was significantly higher compared to the other groups (62.5 vs 41.9 vs 33.7%, respectively, p = 0.006). As expected, most patients (93.1%) presented with chest pain. A quarter of patients (28.7%) reported dyspnoea at the time of primary assessment. As depicted in Fig. 2, patients had multiple overlapping symptoms. There was no significant difference in clinical presentation between the three cohorts. Fig. 3A depicts the time from onset of symptoms to FMC. Across the entire cohort, almost half (46%) of all patients presented more than 12 hours after symptom onset. This was consistent among all three groups. Fig. 3B illustrates the cumulative proportion of STEMI patients that received thrombolysis based on time between symptom onset and FMC. Only 19 (39.6%) STEMI patients received thrombolysis, and 26 (54.1%) received dual antiplatelet therapy and LMWH in hospital. As expected, delayed presentation (> 12 hours) to an appropriate healthcare facility was associated with not receiving thrombolysis (OR 0.07, 95% CI 0.01–0.37). ECG diagnostic accuracy for STEMI was 70.8%. Anterior STEMI (10/48, 20.8%) was the most frequently missed diagnosis. Others included inferior STEMI (3/48, 6.3%) and presumed new left bundle branch block (1/48, 2.1%). None of the patients with a missed STEMI diagnosis received thrombolysis. Furthermore, one patient withUAP, originally incorrectly diagnosed as STEMI, received thrombolysis. The majority of patients presenting with NSTEMI (79.1%) were treated acutely with antiplatelet therapy and LMWH. Table 1. Baseline characteristics (including demographics, co-morbidities and medication, point of first medical contact and outcome) as classified by diagnosis Characteristics Total (n = 174) STEMI (n = 48) NSTEMI (n = 43) UAP (n = 83) p-value Demographics Age, median (IQR) 59.5 (50–68) 55.0 (47– 64) 63.0 (53–72) 60.0 (50– 68) 0.028 Male gender, n (%) 103 (59.2) 37 (77.1) 21 (48.8) 45 (54.2) 0.010 Co-morbidities, n (%) Hypertension 118 (67.8) 28 (58.3) 29 (67.4) 61 (73.5) 0.20 Diabetes mellitus 59 (33.9) 13 (27.1) 16 (37.2) 30 (36.1) 0.50 Dyslipidaemia 50 (28.7) 13 (27.1) 8 (18.6) 29 (34.9) 0.15 Smoking history 84 (48.3) 34 (70.8) 15 (34.9) 35 (42.2) < 0.001 Previous myocardial infarction 53 (30.5) 13 (27.1) 13 (30.2) 27 (32.5) 0.81 Retroviral disease 7 (4.0) 2 (4.2) 3 (7.0) 2 (2.4) 0.46 Family history of ACS 12 (6.9) 2 (4.2) 5 (11.6) 5 (6.0) 0.34 Respiratory (COPD/PTB) 14 (8.0) 3 (6.2) 2 (4.7) 9 (10.8) 0.42 Number of co-morbidities, median (IQR) 2 (1–3) 2 (1–3) 2 (1–3) 2 (1–3) 0.47 Medication, n (%) On treatment 101 (58.0) 20 (41.7) 25 (58.1) 56 (67.5) 0.016 Defaulted treatment 73 (43.7) 28 (62.5) 18 (41.9) 27 (33.7) 0.006 Point of first medical contact, n (%) Primary level 48 (27.6) 26 (54.2) 8 (18.6) 14 (26.9) < 0.001 Secondary level 126 (72.4) 22 (45.8) 35 (81.4) 69 (83.1) < 0.001 Outcome, n (%) Thrombolysis 20 (11.49) 19 (39.58) 0 1 (1.20) 0.000 Local ACS protocol 104 (59.77) 26 (54.17) 34 (79.07) 44 (53.01) 0.012 Survival 171 (98.27) 46 (95.83) 43 (100) 82 (98.79) 0.026 Demised 3 (1.7) 2 (4.2) 0 (0.0) 1 (1.2) 0.026 Referred for PCI 15 (7.5) 5 (10.4) 10 (23.3) 0 < 0.001 NSTEMI, non-ST-segment elevation myocardial infarction; STEMI, ST-segment elevation myocardial infarction; UAP, unstable angina pectoris; ACS, acute coronary syndrome; COPD, chronic obstructive pulmonary disease; PTB, pulmonary tuberculosis; PCI, percutaneous intervention. Non-cardiac chest pain n = 38 Incomplete data n = 2 STEMI n = 48 STEMI n = 9 UAP n = 83 UAP n = 27 40 cases excluded NSTEMI n = 43 NSTEMI n = 11 Patients with suspected ACS n = 214 First presentation of confirmed ACS cases n = 174 First Presentation Second Presentation n = 4 n = 3 n = 3 n = 5 n = 6 n = 7 n = 3 n = 2 n = 14 Fig. 1. Study flow.
RkJQdWJsaXNoZXIy NDIzNzc=