|Year : 2014 | Volume
| Issue : 1 | Page : 27-32
The clinical spectrum of acute coronary syndromes: A study from tertiary care centre of Kumaun region of Uttarakhand
Yatendra Singh1, Vivekanand Satyawali1, Arun Joshi2, Subhash C Joshi1, Mohammad Khalil1, Jainendra Kumar1
1 Department of Medicine, Government Medical College, Haldwani, Uttarakhand, India
2 Department of Cardiology Unit, Government Medical College, Haldwani, Uttarakhand, India
|Date of Web Publication||7-Apr-2014|
Department of Medicine, Government Medical College, Room No. 32, SR Hostel, Haldwani, Uttarakhand
Source of Support: None, Conflict of Interest: None
Background: The clinical profile and the mortality rate among patients with acute coronary syndromes (ACS) is not well-studied in Kumaun region of Uttarakhand.
Objective: The aim of the present study is to determine the clinical characteristics, mortality rate and possible risk factors for high mortality among patients with ACS in Kumaun region of Uttarakhand.
Methods: Retrospective analytic study conducted at Dr. Susheela Tiwari hospital associated with Government Medical College, Haldwani. All the cases admitted to the coronary care unit of Dr. Susheela Tiwari hospital, between May 2012 and April 2013 were included. Cases were grouped into ST-segment elevation myocardial infarction (STEMI) and non-STEMI/unstable angina (NSTEMI/UA) for the purpose of analysis. Chi-square test and unpaired t-test.
Results: Mean age of presentation was 55.86 ± 13.4 years. Mortality rate was higher among patients with inferior wall infarctions when compared with anterior wall infarctions (12.94% vs. 7.14%; P < 0.05). ACS cases with co-existent cardiovascular risk factors such as diabetes mellitus (DM), dyslipidemia, obesity and previous coronary artery disease (CAD) reveal statistically significant higher risk for death when compared to those without these risk factors. Mortality rate was higher among patients with inferior wall infarctions when compared to anterior wall infarctions (12.94% vs. 7.14%; P < 0.05).
Conclusions: Mortality rates among patients was 10.95%. ACS Subjects with DM, dyslipidemia, obesity, previous CAD history and elderly individuals had greater mortality rates and are high risk groups. Among the patients with NSTEMI/UA females had higher mortality rate. Hence, these findings can be taken into account during management of ACS patients.
Keywords: Acute coronary syndrome, non-ST-segment elevation myocardial infarction, ST-segment elevation myocardial infarction, unstable angina
|How to cite this article:|
Singh Y, Satyawali V, Joshi A, Joshi SC, Khalil M, Kumar J. The clinical spectrum of acute coronary syndromes: A study from tertiary care centre of Kumaun region of Uttarakhand. Nig J Cardiol 2014;11:27-32
|How to cite this URL:|
Singh Y, Satyawali V, Joshi A, Joshi SC, Khalil M, Kumar J. The clinical spectrum of acute coronary syndromes: A study from tertiary care centre of Kumaun region of Uttarakhand. Nig J Cardiol [serial online] 2014 [cited 2020 Aug 13];11:27-32. Available from: http://www.nigjcardiol.org/text.asp?2014/11/1/27/130076
| Introduction|| |
Coronary artery disease (CAD) is the leading cause of mortality and morbidity in the world and acute coronary syndromes (ACS), which encompass unstable angina (UA), non-ST-segment elevation myocardial infarction (NSTEMI) and STEMI, are the most common causes of mortality in patients with CAD. With the introduction of a huge armamentarium of invasive and non-invasive therapeutic strategies, the mortality related to ACS has significantly reduced in the developed world over the past 20 years. ,,,,, However, the mortality remains high among Indians. ,,,,, CAD occurs in Indians 5-10 years earlier than in other populations around the world and the major effect of this peculiar phenomenon is on the productive workforce of the country aged 35-65 years.  The prevalence of CAD and the incidence of ACS also are very high among Indians. ,,,, India has the highest burden of ACS in the world.  The rising incidence of ACS in Indians may be related to the changes in the life-style, the westernization of the food practices, the increasing prevalence of diabetes mellitus (DM) and probably genetic factors. CREATE registry, the largest data from Indian patients with ACS, has shown that the pattern of ACS among Indians is much different from that of the Western populations.  The health status of Uttarakhand population differs from that of other Indian states owing to its three distinct geographical regions, (i) the high mountain region, the (ii) mid-mountain region and (iii) the Terai region. Poor distribution of its healthcare among hilly and non-hilly areas and its poor access to healthcare institutions by areas.
The clinical spectrum, the age and gender-specific differences and the mortality rate in patients with ACS are not studied properly in the Kumaun region of Uttarakhand on a large scale basis. In this background, this study was performed using the data extracted from the case records of patients treated with ACS between May 2012 and April 2013 in the cardiology unit, Department of Medicine of Dr. Susheela Tiwari Government Medical College and Hospital, one of the biggest referral centers and a tertiary-care teaching hospital in the Kumaun region of Uttarakhand.
| Materials and Methods|| |
Case records of all the cases admitted to the coronary care unit of Dr. Susheela Tiwari hospital associated with Government Medical College Haldwani, between May 2012 and April 2013 were searched. A type of retrospective, analytic study was conducted from data collected. Those cases with proven non-cardiac chest pain and those with incomplete records, were excluded from the analysis. The cases were grouped into two; viz., those presented with STEMI and those presented with NSTEMI/UA, for the purpose of analysis. Cases of chest pain/discomfort with elevation of ST-segment in electrocardiographic (ECG) leads/presumed new onset left bundle branch block in ECG were categorized as STEMI. Cases of angina at rest without ST-segment elevation were categorized as NSTEMI if their cardiac Troponin T (Trop T) levels exceeded 0.1 ng/ml and as UA if their Trop T levels were lower.
The baseline clinical characteristics analyzed in each group were the age, gender, hypertension (blood pressure >140/90 mmHg and/or those already taking treatment for hypertension), DM (fasting blood glucose >126 mg/dL and/or postprandial blood glucose >200 mg/dL and those who were on treatment for DM), dyslipidemia (cholesterol >200 mg/dL and/or triglycerides >150 mg/dL), smoking status, duration of chest pain before hospitalization, the mean duration of hospital stay and complications related to the ACS and its treatment.
In cases with STEMI, the details of the area of myocardium infarcted, the hemodynamic subset (Killip class), the associated mechanical complications and conduction abnormalities, whether thrombolytic therapy was received or not, post-infarction angina, reinfarction, pericarditis and arrhythmias were analyzed.
The causes of death and the risk factors for high mortality in patients with ACS were also analyzed. The clinical parameters and outcomes in the patients (aged more than 45 years) with STEMI were compared with those of the younger patients (aged <45 years). A comparison of clinical parameters between males and females and between STEMI and NSTEMI/UA also was done.
Statistical analysis was performed using the software SPSS for Windows, Version 16.00. Categorical variables were compared by Chi-square test and the continuous variables are presented as mean (±standard deviation) and were compared by unpaired t-test. P < 0.05 was considered to be statistically significant.
| Results|| |
A total of 512 cases were admitted to the coronary care unit during the study period with suspected ACS, of which, 429 cases fulfilled the inclusion criteria and their data was analyzed in the study. Totally 83 patients who either did not fulfill the inclusion criteria or had incomplete records were excluded from analysis. Higher number of patients were from Terai/plain region (294; 68.6%) when compared to hilly region (135; 31.4%). Mean age of presentation was 55.86 ± 13.4 years. Mean age of presentation of female patients was significant higher than male patients (66.41 ± 13.1 vs. 52.49 ± 11.7, P < 0.001). 325 were males (75.8%) and 104 were females (24.2%). 47 (10.95%) patients died during the in hospital treatment. Geographically mortality was higher in patients presented from hilly areas as compared to plain/Terai region (20, 14.8% vs. 17, 5.8%). Thirty eight patients (8.8%) were referred for coronary interventions because of post-infarction angina and persistent shock or chronic heart failure or heart block.
Of the 429 cases of ACS, 65.50% had STEMI and 34.50% had NSTEMI/UA. Mean age of presentation of STEMI cases was 56.10 years and that of NSTEMI/UA was 55.30 years.
A comparison of the clinical characteristics of patients with ACS is shown in the [Figure 1]. In females with ACS, NSTEMI/UA outnumbered STEMI (31.76% vs. 20.28%; P < 0.05); whereas in males STEMI outnumbered NSTEMI/UA (79.72% vs. 68.24%; P < 0.05). ACS cases with co-existent cardiovascular risk factors such as, hypertension and smoking history did not reveal any statistically significant higher risk for death when compared to those without these risk factors. ACS cases with co-existent cardiovascular risk factors like DM, dyslipidemia, obesity and previous CAD reveal statistically significant higher risk for death when compared to those without these risk factors.
|Figure 1: The comparison between the clinical parameters among patients with non-ST-segment elevation myocardial infarction/unstable angina and those with ST-segment elevation myocardial infarction|
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ACS cases with co-existent other symptoms (palpitation, sweating), history of alcohol intake, non-vegetarian diet family history did not reveal any statistically significant higher risk for death when compared to those without these factors. The majority of patients were aged between 41 and 55 years. Nearly 72% of patients were above the age of 45 while 27% were below 45 [Figure 2]. [Table 1] shows comparison of the clinical characteristics between the elderly individuals and younger subjects with ACS.
|Table 1: The comparison of the clinical characteristics between the elderly individuals and younger subjects with acute coronary syndrome|
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Patients with STEMI
One sixty cases (56.9%) of STEMI presented with central chest discomfort, 80 (28.5%) with left-sided chest pain, 17 (6%) with right-sided chest pain and 5 (1.8%) with jaw pain. 19 cases presented with acute onset of palpitation and/or collapse due to ventricular tachycardia (VT). The majority of cases were transported to the hospital by either ambulance (108) or private vehicle. Sex distribution, mean age of cases, mean duration of symptoms before admission, known major cardiovascular risk factors and treatments (thrombolysis) received in the hospital are depicts in [Table 2]. Mean time interval before receiving thrombolysis after hospitalization was 40 ± 16 min. On categorizing the patients according to the hemodynamic subsets, 220 patients (78.3%) with STEMI belonged to Killip class I, 10 (3.6%) belonged to class II, 13 (4.6%) to class III and 38 (13.5%) to class IV at the time of admission to the hospital.
|Table 2: The baseline characteristics among males and females with ST-segment elevation myocardial infarction|
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Among the patients with STEMI, 139 (49.5%) had inferior wall and 140 (49.8%) had anterior wall infarctions. Remaining 2 were lateral wall and posterior wall infarctions. Out of those with inferior wall infarctions, 60 (43.2%) cases had associated right ventricular infarctions, 11 (7.9%) had advanced second degree atrioventricular-block and 8 (5.6%) had complete heart block. In total, 60 patients could not be thrombolysed. The reasons for not administering thrombolytic therapy was the late presentation of cases in 48 (80%) patients and other reasons were due to: Non-satisfactory ECG criteria, absence of typical chest pain, affordability issue, contra-indications for thrombolysis in patients.
The mean duration of hospital stay in patients with STEMI was 4 ± 2 days. In-hospital complications noticed among patients with STEMI were left ventricular failure in 54 (19.21%) post-myocardial infarction angina in 29 (10.32%), reinfarction in 19 (6.76%), pericarditis in 12 (4.27%) and severe mitral regurgitation in 8 (2.84) patients.
Commonest arrhythmia encountered was ventricular premature beats that occurred in 78 (27.75%) patients. Other arrhythmias observed were accelerated idioventricular rhythm (AIVR) in 40 (14.23%), VT in 28 (9.96%), atrial fibrillation (AF) in 27 (9.60%) and ventricular fibrillation (VF) in 40 (14.23%) patients. 28 (9.97%) patients with STEMI died during the treatment. Patients with age >45 years had higher mortality rates (compared to younger individuals) and 24 (11.59%) out of 207 patients in this group died during treatment (P < 0.05). Females with STEMI did not show any significant difference in mortality rates when compared to males (10.52% vs. 9.82%; P > 0.05). Mortality rate was higher among patients with inferior wall infarctions when compared to anterior wall infarctions (12.94% vs. 7.14%; P < 0.05).
Those who received thrombolytic therapy had a lower mortality rate (6.76% vs. 15%; P < 0.05). The mortality rate increased with advancing age, with lower rate in those patients who were < 45 years of age (5.40%) as compared to those who were more than 45 years of age (11.6%). The mortality rates in various hemodynamic subsets were as follows: Killip class I-4.1%, class II-5.6%, class III-15.3% and class IV-42.1%.
Mechanisms of death in STEMI
Ventricular pump failure 8 (28.6%) and VF in 8 (28.6%), were the commonest causes of death. The other causes of death were asystole in 6 (21.4%) and electromechanical dissociation in 4 (14.3%) and multi-factorial in 2 (7.14%) patients. Asystole was more common in inferior wall infarction when compared to anterior wall infarctions (28% vs. 7%; P = 0.001). Electromechanical dissociation was seen only in anterior wall infarctions.
STEMI in >45 years of age
There were 207 patients above the age of 45 years with STEMI in the present study and their clinical characteristics are compared with those at younger ages (<45 years) as shown in [Table 3].
|Table 3: The comparison of the clinical characteristics between the elderly individuals (>45 years) and younger (<45 years) subjects with ST-segment elevation myocardial infarction|
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Out of the 207 elderly patients with STEMI, 24 died (mortality rate 11.6%). Those patients with age more than 45 years of age, who received thrombolytic therapy, had higher rate of mortality (9.2% vs. 0%; P < 0.05). The reason for not administering thrombolytic therapy was delayed presentation most of the cases.
Patients with NSTEMI/UA
Of the 148 patients in this group, 53 (35.81%) had raised levels of Trop T (>0.1 ng/ml) and they were categorized as NSTEMI cases and the remainder were grouped as UA cases. Among the NSTEMI/UA cases, 75 patients (50.7%) presented with central chest pain, 40 (27.0%) with left-sided chest pain and 20 (13.5%) with right-sided chest pain. 13 cases (8.7%) were admitted with palpitation/collapse secondary to VT. Mean duration of hospital treatment was 3.7 ± 2.8 days. Sex distribution and mean age of cases, mean duration of symptoms before admission, known major cardiovascular risk factors are depicted in [Table 4]. 10 (6.7%) were referred for coronary interventions because of persistent angina despite adequate medical treatment.
|Table 4: The baseline parameters among males and females with non-ST-segment elevation myocardial infarction|
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In-hospital complications noticed in patients with NSTEMI were left ventricular failure in 18 cases (12.2%), mitral regurgitation in 4 (2.7%) patients. Commonest arrhythmia encountered was ventricular premature beats that occurred in 48 (32.4%) patients. Other arrhythmias observed were AIVR in 20 (13.5%), VT in 15 (10.1%), AF in 12 (8.1%) and VF in 3 (2.0%) patients. Among the patients with NSTEMI/UA females had higher mortality rate (8.1% vs. 4.72%, P < 0.05), but there was statistically significant differences in the mortality rates between those with and without the history of smoking, DM and dyslipidemia.
| Discussion|| |
The mean age at presentation of ACS cases (55.9 years) is comparable with mean age of cases from the CREATE registry data (57.5 years).  Mean age of presentation of female patients was significant higher than male patients (66.41 ± 13.1 vs. 52.49 ± 11.7, P < 0.001), similar findings were observed in DEMAT registry.  The mean age at presentation of patients with STEMI was 56.10 years in this study, which is comparable to observations of CREATE registry  and another study by Jose and Gupta (56 years).  About 78.6% of STEMI cases received thrombolytic therapy. Around 10% (9.96%) of STEMI cases died during treatment. Ventricular pump failure 8 (28.6%) and VF in 8 (28.6%), were the commonest causes of death. Cases with inferior wall infarctions, higher Killip class at admission, DM and age more than 45 years, had higher mortality rates. Higher proportion NSTEMI/UA cases in comparison to STEMI cases had hypertension (56.75% vs. 42.35%) and were females (31.76% vs. 20.28%). Mean duration of symptoms before hospitalization was higher in NSTEMI/UA group as compared to STEMI group (21.1 h vs. 11.37 h). Mortality was higher in patients presented from hilly areas as compared to plain/Terai region (20, 14.8% vs. 17, 5.8%). This might be due to higher mean duration of symptoms before hospitalization in patients of hilly region (24.2 h vs. 8.6 h).
This study also showed a higher proportion of STEMI cases among patients with ACS as observed in the CREATE registry and DEMAT Registry. Though we observed an in-hospital mortality rate of 10.95% that was much higher than the mortality rate observed among ACS cases in the CREATE registry (5.6%), DEMAT Registry (2%). , Two reasons might be there for higher mortality in this study, first in above studies management part also included coronary interventions and second our study included significant number of patients (31.2%) from hilly region, who presented late. It was slightly higher than the study conducted by Misiriya et al. (8.04%) in Kerala.  In this study, patients was managed conservatively as in our study, so we expected higher mortality because of different geography and poor access to health facility in Uttarakhand. It can be explained because in our study around 68.8% were from Terai or plain region, that might be reason for this slight difference in mortality. Mortality in STEMI (9.96%) was comparable to study conducted by Misiriya et al. (11.97%), Kerala ACS Registry (8.2%). , It was much lower than study conducted by Jose and Gupta (16.9%).  On comparing mortality in NSTEMI (12.84%), it was much higher to study conducted by Misiriya et al. (3.05%). 
The mean duration of symptoms before hospitalization (i.e. 11.37 h) in STEMI patients was much higher than observed in other Indian studies Misiriya et al. (3.5 h), CREATE registry (6 h). , The reason might be due to poor access to health facilities among the population of Uttarakhand, mainly from hilly areas. Male preponderance was observed in the patients with STEMI at all age-groups. The sex ratio observed in both the younger and older age-groups was comparable another series reported from North India Holay et al. 
As observed in other studies Steg et al. and Jose and Gupta, significantly higher numbers of females with STEMI had risk factors like DM and dyslipidemia. , The higher mean age at presentation may be a contributing factor for the increased prevalence of these risk factors among them. Higher proportions of STEMI cases in our study, when compared to those from CREATE registry received thrombolytic therapy (78.6% vs. 58.5%), DEMAT registry (78.6% vs. 45%) and comparable to study conducted by Jose and Gupta. ,,
Patients with anterior wall and inferior wall STEMI observed in this study were almost equal. It was not consistent with study done by Jose and Gupta,  where anterior wall myocardial infarction percentage was more as compared to inferoposterior wall myocardial infarction. The hemodynamic subsets (Killip class) did not match in both studies and we observed a higher proportion of cases (78.3%) in Killip class I.
Females with STEMI did not show any significant difference in mortality rates when compared to males (10.52% vs. 9.82%; P > 0.05) as opposite to other studies by Shaukat et al., Tan et al., Jose and Gupta, Koek et al. ,,, Contrary to the earlier study done by Haim et al., Hanania et al., cases with inferior wall STEMI had a higher mortality rate when compared to those with anterior wall STEMI in our study. Right ventricular infarction and conduction system abnormalities encountered in many patients with inferior wall STEMI in our cases, that might explain this disparity in the mortality rates. ,
There was statistically significant higher mortality rate in those who received thrombolytic therapy in elderly (>45 years) patients with STEMI. Delayed presentation was the reason for not administering thrombolytic therapy among the majority of these cases. The reason for delayed presentation and lower mortality rate might be less severe coronary disease among them. Presence of DM in patients with STEMI found to be a significant predictor for high mortality as observed by others.  However, hypertension and history of smoking did not pose any higher risk for in-hospital mortality in our study.
The proportion of NSTEMI/UA among ACS cases in our study was lower than that observed in the CREATE registry 12 (34.50% vs. 39.4%) DEMAT registry (48.37%) and study conducted by Misiriya et al. (44%). ,, The mortality rate observed in patients with NSTEMI/UA (12.84%) was higher than the observations made in other studies CREATE registry (3.7%), Patel et al. (2.36%) and Misiriya et al. (3.05%). This might be because mean duration of symtoms in NSTEMI/UA was higher than STEMI (21.12 vs. 11.37). ,, Among the patients with NSTEMI/UA females had higher mortality rate (8.1% vs. 4.72%, P < 0.05), similar observation was seen by Misiriya et al. 
| Conclusions|| |
The mortality rate of ACS remains high in this study. Mean age of presentation of female patients was significant higher than male patients. Female patients with ACS have higher incidence of NSTEMI/UA than STEMI. Female patients with NSTEMI/UA have higher mortality risk when compared to males and they should be managed more carefully. In STEMI elderly individuals and those with DM should be managed more carefully to reduce the mortality rates. Inferior wall STEMI in our study, had a higher mortality rate when compared to those with anterior wall STEMI. Mortality was higher in patients presented from hilly areas as compared to plain/Terai region. So these factors should be kept in mind while managing STEMI and NSTEMI cases.
First, our sample size was relatively small and was short duration study only at one tertiary care center which have admission from particular region of Uttarakhand. As it was retrospective study no follow-up was taken into account. So larger study at multiple center with proper follow-up may be required to better access the clinical profile and outcome in ACS patients of Kumaun region of Uttarakhand.
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[Figure 1], [Figure 2]
[Table 1], [Table 2], [Table 3], [Table 4]