Clinical profile and management of patients with incident and recurrent acute myocardial infarction in Albania - a call for more focus on prevention strategies

This study included 324 consecutive patients hospitalized during 2013-2014, with an AMI in the Coronary Care Unit (CCU) of the University Hospital Centre ‘Mother Teresa’,’ the only public hospital providing specialized coronary care in Tirana, the capital of Albania.

Information on patients’ age, gender, educational attainment, height and weight, systolic and diastolic blood pressure, AMI type [ST-elevation myocardial infarction (STEMI) versus non-ST-elevation myocardial infarction (NSTEMI)], location, major complications [including heart failure (HF), ventricular fibrillation (VF) and 2nd or 3rd degree atrioventricular block (AVB)], and in-hospital treatment was obtained from patients’ medical charts.

To derive the prevalence of each major risk factor, we combined self-reported information on risk factors and medication use prior to hospitalisation with blood pressure, fasting glucose, and total cholesterol values measured during admission (22). A history of prior AMI was defined as a previous hospitalisation with AMI as the main discharge diagnosis.

Continuous variables were presented as means and standard deviations (SD), and categorical variables were presented as percentages. Independent sample t-test was used to compare mean values of the continuous variables. Categorical variables were compared using the chi-square test or Fisher’s exact test in cases of small sample sizes.

Logistic regression models were used to explore differences between incident and recurrent cases regarding AMI complications and in-hospital treatment. They were adjusted for covariates known to influence the outcome, and showed association with the exposure in our data. To account for the role of comorbidities in a potentially influencing use of beta-blockers [chronic obstructive pulmonary disease (COPD), systolic blood pressure (SBP)<85 mm Hg or AVB], angiotensin-converting enzyme inhibitors (ACEI)/angiotensin receptor blockers (ARB) (SBP<85 mm Hg) and aspirin (peptic ulcer), we repeated the analyses after excluding patients with any of these conditions. The results of these analyses (referred to in the text as ‘additional analyses’) are presented as supplemental material online.

We tested and did not find a statistically significant interaction between gender and history of prior AMI. All models were adjusted for age and gender, and results expressed as odds ratios (OR) and 95% confidence intervals (CI) for prevalent versus incident (the reference category) AMIs. Two-sided tests with the 0.05 significance level were used. Analyses were performed using STATA software, version 13.

Characteristics of the study population are summarized in Table 1. The mean (SD) age of the cohort was 64.4 (11.4) years and the majority (73.8%) were men. Overall, 44.1% of patients had attained only primary education and 55.9% secondary or tertiary education.

Table 1

Characteristics of the study population.

The prevalence of current smoking, hypertension, diabetes mellitus (DM), and hypercholesterolemia was 59.9%, 83.3%, 50.6% and 55.3%, respectively. At least one major risk factor was observed in 98.8%, and all four major risk factors in 13.9% of the study cohort.

STEMI accounted for 83.9% of the study population (Table 2). AMI was complicated with HF in 33.6% of the patients. The proportion of impaired LVEF, 2nd or 3rd degree AVB or VF in the study population were 31.2%, 4.0% and 4.9%, respectively. Compared to incident cases, recurrent cases had multivessel CHD (P=0.03), HF (P<0.01), or impaired LVEF (P=0.01) (Table 2).

Table 2

Clinical profile and in-hospital treatment of patients with an acute myocardial infarction.

The results of age and gender-adjusted analyses revealed an increase in the odds of HF (OR=2.48; 95% CI: 1.31–4.70), impaired LVEF (OR=1.97; 95% CI: 1.05–3.71), or multivessel CAD (OR=6.32; 95% CI: 1.43–28.03) among recurrent cases compared to incident ones. No statistically significant differences were observed between groups regarding AMI type and other complications (Figure 1).

Figure 1

The utilisation rates for beta-blockers, angiotensin-converting enzyme inhibitors (ACEIs)/angiotensin receptor blockers (ARBs), statins, and aspirin were 59.3%, 63.6%, 96.9%, and 95.1%, respectively (Table 2).

Less than half (44.4%) of the study population received all four drug classes. Only 68.5% of the patients underwent coronary angiography. Of those, 64.4% received coronary revascularisation. The proportion of patients receiving a beta-blocker or statin was lower among recurrent compared to incident cases (P=0.01 and P=0.03, respectively). No statistically significant differences in the utilisation of other drug classes or invasive diagnostic and treatment procedures were observed between the two groups.

Adjusted analyses revealed lower utilisation rates of beta-blockers among recurrent cases as compared to incident cases (OR=0.45; 95% CI: 0.24–0.85) (Figure 2).

Figure 2

No statistically significant differences between groups were observed regarding ACEIs/ARBs, statins or aspirin use [(OR=0.67; 95% CI: 0.36–1.26), (OR=0.34; 95% CI: 0.12–1.31) and (OR=1.15; 95% CI: 0.30–1.31), respectively].

A similar pattern was observed in the use of invasive diagnostic and treatment procedures. No statistically significant differences between the two groups were found with regard to coronary angiography (OR=0.88; 95% CI: 0.45–1.71) or revascularisation (OR=0.67; 95% CI: 0.30–1.49).

The results of additional analyses were similar to those of the main analyses in terms of direction of the association and level of significance (Table 1, supplementary material online).

The burden of coronary risk factors in our study was very high among both incident and recurrent cases. The prevalence of HF, impaired LVEF, and multivessel CAD (all reliable indications of AMI’s clinical severity) were higher among recurrent compared to incident cases. The use of evidence-based drugs in our study varied widely and, compared to incident cases, recurrent cases seemed to use less often evidence-based treatment, including revascularisation. However, the differences were statistically significant only with regard to the use of beta-blockers.

Data from a case-control study conducted in Tirana between 2003 and 2006, and enrolling 467 acute coronary syndrome (ACS) patients (i.e., a combination of AMI and unstable angina pectoris – UAP), revealed that the prevalence of obesity (BMI≥30), hypertension, DM, and current smoking were 20.6%, 29.6%, 15.8%, and 42.2%, respectively (23). Among 809 incident ACS cases admitted to CCU in Tirana in 2009, the prevalence of current smoking, hypertension, family history of CHD, and overweight/obesity were 63%, 58%, 33%, and 30%, respectively. All patients had at least two coronary risk factors (24).

Several factors may have contributed to the higher burden of coronary risk factors in our study, compared to other studies conducted in Albania (23, 24). We included in the analyses, only AMI patients, while others combined AMI and UAP patients. Further, the study by Balla et al. (24) included only incident cases, while our study population was a mixture of incident and prevalent cases. Our study population comprised severely ill patients requiring hospitalisation in CCU, whereas in the study by Burazeri et al. (23), patients were recruited from CCU and hospital wards. Despite these differences in the populations studied, a worrying increase in the burden of risk factors over time cannot be rule out, and needs further investigation.

Internationally, the prevalence of smoking, hypertension, DM, and hyperlipidaemia among 122 458 CHD patients enrolled in 14 randomised control trials was 37.9%, 43.2%, 17.5%, and 34.8%, respectively. Eighty-two percent of patients had at least one, whereas 1.0% of the cohort had all four major coronary risk factors (25). Data from the National Cardiovascular Registry (NCDR) showed that 71.4% of AMI patients reported to suffer from hypertension, and 30.5% from DM (26).

We could not identify previous publication from Albania comparing incident and recurrent cases regarding their clinical profile or in-hospital treatment. International studies have suggested that recurrent cases presented more often with pulmonary oedema, cardiogenic shock and asystole (27), and have a higher incidence of HF (28), compared to incident cases.

The results of the analyses comparing in-hospital treatment between incident and recurrent cases have been less consistent. In the Netherlands, utilisation rates of aspirin, beta-blockers, and statins among 4718 STEMI patients were higher in incident, compared to recurrent cases (9). In the USA, similar rates were reported in incident and recurrent cases (28). With regard to revascularisation procedures, higher rates were observed in incident, compared to recurrent cases in the USA (28) and Israel (27). The direction of the association in our study suggests a more severe clinical expression of the disease with concurrent lower utilisation rates of medications in recurrent compared to incident cases. However, due to the lack of statistical significance (possibly affected by the relatively small sample size), these findings should be interpreted with caution.

A direct comparison of our findings with previously published analyses on the use of invasive procedures is challenging, as the use of these procedures is largely influenced by patients’ age, gender, comorbidities, prior AMI status, and the study period – all factors that differ widely between the published studies.

The high burden of coronary risk factors reflects the lack of prevention measures in the population at large in Albania. Interventions aiming at reducing the burden of coronary risk factors have proven to be cost-effective (29), and can reduce CHD mortality up to 75% (30-33). Nevertheless, the majority of resources in the past 2-3 decades were allocated into tertiary care institutions, aiming at modernising the system and improving the quality of care. The observed unfavourable trends in CHD mortality in Albania, combined with our findings, point out to the immediate need for a shift in the focus of attention toward preventive measures. In 2014, health authorities launched a nationwide health campaign, inviting citizens aged 40-65 years (expanded lately to include those aged 35-70 years) to undergo a medical examination aiming at screening for CVD (with a special focus on CHD), cancer, and other relevant conditions. This was the first step in the long process of identifying the burden of coronary risk factors in the population. This campaign can lay the ground for policy and legislative changes to tackle many aspects related to diet and lifestyle, aiming at reducing the burden of risk factors and, subsequently, CHD in Albania.

Another worrying finding is the prevalence of risk factors among recurrent cases, which – with an exception of smoking – is similar to (if not higher than) that of incident cases. This reflects the failure of patients with overt CHD to change their risk profile and conduct a healthy lifestyle. Many factors may have contributed to this failure, including i) the lack of personalised recommendations upon discharge from the hospital, ii) lack of rehabilitation programs, iii) poor adherence to treatment, iv) no coordination between different actors involved in the health care system (i.e., the family doctor and specialist) during the follow up. Further studies are needed to tackle each potential component individually and provide a new insight into this phenomenon. Further, national guidelines specifying treatment goals, frequency of follow up visits and role of specialist (versus the family doctor) during the follow up are needed to optimise medical care and reduce the rate of new coronary events in this vulnerable subset of population.

Recurrent cases present with a more severe form of the disease, yet, the medication use among them tend to be suboptimal compared to that in incident cases. The reasons for these differences are not clearly explained. One hypothesis is that certain comorbidities and/or AMI complications represent contraindications to individual cardiac drugs. We addressed this issue by conducting additional analyses where we excluded patients with such comorbidities and/or AMI complications. This was associated with a slight increase in the use of beta-blockers (+ 2.4%), ACEI/ARBs (+2.4%), statins (+0.9%), and all four drug classes (+3.8%). However, the differences in the use of cardiac drugs between recurrent and incident cases did not change substantially, indicating that factors other than comorbidities might be involved.

Another reason might be related to the fact that medical staff is reluctant to perform revascularisation procedures among severely ill patients due to a poorer outcome compared to that in uncomplicated AMI cases (34).

Our study has several limitations. The relatively small sample size and low number of patients with a recurrent event, is most probably responsible for the statistically non-significant findings, even though the point estimates indicate that recurrent AMIs present at the hospital with a more severe clinical expression, and underutilise the recommended drug classes compared to incident AMIs.

Our sample size did not allow us to explore the role of medications taken prior to hospitalisation on the burden of risk factors, either. Furthermore, we could not determine the proportion of patients with controlled level of risk factors. In addition, we did not know the proportion of patients who might have been scheduled to receive revascularisation upon AMI discharge, as followup information was not available. We therefore restricted our focus on treatment during MI hospitalization. The distinction between ‘never’ and ‘former’ smokers was not available in our study. Consequently, we could not discriminate between patients who smoked and gave up smoking, and those who never smoked. This distinction would have been of particular interest among recurrent cases. We also lacked information on the time from symptom onset to arrival at the hospital; an important factor influencing the decision to perform coronary angiography and revascularisation.