Scholarly article on topic 'Mortality in myocardial infarction remains high in Argentina: The association with health insurance coverage'

Mortality in myocardial infarction remains high in Argentina: The association with health insurance coverage Academic research paper on "Health sciences"

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Abstract of research paper on Health sciences, author of scientific article — Hernán Cohen Arazi, Claudio Higa, Patricia Blanco, Sebastián Nani, Horacio Fernandez, et al.

Abstract Objectives The present analysis included patients with myocardial infarction from the SCAR registry in Argentina. It reports how health insurance coverage influenced the outcomes. Methods Eighty-seven centers participated in a cross-sectional nation-wide multicenter survey. Results Seven hundred and fifty-eight patients were included, 476 (60.55%) with STEMI and 281(39.45%) non-STEMI (NSTEMI). In-hospital mortality was 7.35%. Mortality was independently associated with age (OR 1.06, CI95 1.02–1.1, p=0.001), left ventricular dysfunction (OR 7.12, CI95 2.5–20, p<0.001), and Killip 3–4 (OR 4.86, CI95 1.64–14,p=0.004). Treatment with ACEi (OR 0.18, CI95 0.06–0.48, p<0.005) and beta-blockers (OR 0.22, CI95 0.07–0.62, p=0.05) was associated with lower mortality. In STEMI, the mean time from symptom onset to admission was 120min (60–330) for patients arriving from home, and 240min (120–510) for patients referred from other institutions. 285 patients underwent PCI with mean door-to-balloon time of 107min (60–231); 92 patients received thrombolysis (mean door-to-needle time of 55min (29–90)). Mortality in STEMI was 8%, which was independently associated with age (OR 1.09, CI95 1.04–1.14, p<0.001), Killip 3–4 (OR 3, CI95 1.24–12.8, p=0.02), and inotrope requirement (OR 19, CI95 6–60, p<0.001). Door-to-balloon time <90min for primary PCI was independently associated with a significant reduction in mortality (OR 0.11, CI0.01–0.68, p=0.001) in STEMI. We observed significant differences in the rate of PPCI and time to reperfusion according to the insurance coverage that might have influenced the outcomes. Conclusions Outcomes in AMI were affected by insurance coverage. Efforts to improve reperfusion rates and delay to treatment are necessary.

Academic research paper on topic "Mortality in myocardial infarction remains high in Argentina: The association with health insurance coverage"

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IJC Metabolic & Endocrine

journal homepage: http://www.journals.elsevier.com/ijc-metabolic-and-endocrine

Mortality in myocardial infarction remains high in Argentina: fllWst

The association with health insurance coverage

Hernán Cohen Arazi *, Claudio Higa, Patricia Blanco, Sebastián Nani, Horacio Fernandez, Alfredo Hirschson, Jorge G. Allin, Ernesto Duronto

Consejo de Emergencias Cardiovasculares, Dr. Rafael Bullrich, Sociedad Argentina de Cardiología, Argentina

ARTICLE INFO

ABSTRACT

Article history: Received 30 July 2014 Accepted 10 August 2014 Available online 15 August 2014

Keywords:

Myocardial

Infarction

Registry

Mortality

Health

Insurance

Objectives: The present analysis included patients with myocardial infarction from the SCAR registry in Argentina. It reports how health insurance coverage influenced the outcomes.

Methods: Eighty-seven centers participated in a cross-sectional nation-wide multicenter survey.

Results: Seven hundred and fifty-eight patients were included, 476 (60.55%) with STEMI and 281(39.45%) non-

STEMI (NSTEMI).

In-hospital mortality was 7.35%. Mortality was independently associated with age (OR 1.06, CI95 1.02-1.1, p = 0.001), left ventricular dysfunction (OR 7.12, CI95 2.5-20, p < 0.001), and Killip 3-4 (OR 4.86, CI95 1.64-14, p = 0.004). Treatment with ACEi (OR 0.18, CI95 0.06-0.48, p < 0.005) and beta-blockers (OR 0.22, CI95 0.07-0.62, p = 0.05) was associated with lower mortality.

In STEMI, the mean time from symptom onset to admission was 120 min (60-330) for patients arriving from home, and 240 min (120-510) for patients referred from other institutions. 285 patients underwent PCI with mean door-to-balloon time of 107 min (60-231); 92 patients received thrombolysis (mean door-to-needle time of 55 min (29-90)).

Mortality in STEMI was 8%, which was independently associated with age (OR1.09, CI95 1.04-1.14, p < 0.001), Killip 3-4 (OR 3, CI95 1.24-12.8, p = 0.02), and inotrope requirement (OR 19, CI95 6 -60, p < 0.001). Door-to-balloon time <90 min for primary PCI was independently associated with a significant reduction in mortality (OR 0.11, CI0.01-0.68, p = 0.001) in STEMI.

We observed significant differences in the rate of PPCI and time to reperfusion according to the insurance coverage that might have influenced the outcomes.

Conclusions: Outcomes in AMI were affected by insurance coverage. Efforts to improve reperfusion rates and delay to treatment are necessary.

© 2014 The Authors. Published by Elsevier Ireland Ltd. This is an open access article under the CC BY-NC-ND license

(http://creativecommons.org/licenses/by-nc-nd/3.0/).

1. Introduction

Coronary artery disease remains a major public health problem in Latin America, especially in Argentina [1]. The GRACE has shown worse outcomes among Latin American patients with acute myocardial infarction (AMI) compared with European and American patients [2]. Data from international registries may not be representative of the patient population in Argentina due to differing characteristics and health policies.

Insurance coverage may affect mortality and clinical outcomes in patients with AMI [3]. Little information is available on the potential of insurance systems to reduce inequalities in the treatment and outcomes of acute coronary syndromes.

* Corresponding author. E-mail address: h_c_arazi@yahoo.com (H.C. Arazi).

The present report is a prespecified sub-analysis of patients with AMI from the global SCAR (Síndrome Coronario Agudo en Argentina) registry that included all ACS (myocardial infarction and unstable angina), performed to evaluate patient characteristics, procedural details and inhospital outcomes. The present analysis reports how health insurance coverage influenced treatment and outcomes in Argentina.

2. Material and methods

The SCAR registry was conducted by the research area and the Cardiovascular Emergency Council of the Argentine Society of Cardiology (SAC). It was a cross-sectional nation-wide multicenter survey developed in Argentina. Data from patients were uploaded to a web site.

Cardiologists who participated in the registry were advised not to modify any therapeutic strategies and treatment was left to the discretion of the physician.

http://dx.doi.org/10.1016/j.ijcme.2014.08.004

2214-7624/© 2014 The Authors. Published by Elsevier Ireland Ltd. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/3.0/).

The study was conducted in compliance with Good Clinical Practices, Argentine laws and Argentine data protection laws. No individual specific consent forms for the study were obtained. The protocol was reviewed and approved by an independent ethics committee and approved by internal committees in each institution.

The patients included in the analysis had a diagnosis of AMI with at least two of the following inclusion criteria: symptoms of myocardial ischemia for >20 min, ST segment changes or T wave inversion in two leads compatible with myocardial ischemia, or new left bundle branch block, or development of new abnormal Q waves, elevation of troponins or CK-MB.

ST-segment elevation myocardial infarction (STEMI) was diagnosed when ST-segment elevation > 1 mm was observed in at least two contiguous leads in EKG, or when a new left bundle branch block or new abnormal Q waves developed.

Patients with MI >24 h, secondary angina and patients without typical angina were excluded for the present analysis.

Every medical institution affiliated to SAC was invited to participate in the registry through a mail letter. Eighty-seven centers in Argentina (academic institutions, community hospitals and private hospitals) agreed to participate. Fifty five percent of the participating centers had a Cardiology Fellow Program, 77% had a Cardiac Catheterization Laboratory for Primary Angioplasty (PCI) available 24 h a day, 7 days a week; and 74% had a Cardiovascular Surgery Service.

Patients were consecutively recruited from intensive care units (ICU) or cardiology departments. The centers were incorporated to the registry in different periods, between March and October 2011, and everyone included patients during a three month period. A computerized case record form (CRF) was filled-in for each eligible patient, and data was recorded on-line. In the case of missing data, an investigator from the SAC contacted the local investigator to obtain any missing information.

The following data were collected: cardiovascular and non-cardiovascular medical history, cardiovascular risk factors, clinical progression including symptoms on admission and Killip-Kimball class, therapeutic management, laboratory tests and in-hospital outcomes. Health insurance data was recorded: it included private insurance, "obras sociales" (OS) which are organizations that manage health coverage for people who are still working or retired, and uninsured people, who depend on health assistance at public hospitals.

2.1. Statistical analyses

For quantitative variables, means, standard deviations, interquartile range (IQR), as well as minimum and maximum values were calculated. Discrete variables were presented as percentages. Comparisons were made with chi-square or Fisher's exact tests for discrete variables, and by unpaired T test, Mann-Whitney U test or Wilcoxon signed-rank test for continuous variables.

There are no official data about the incidence of myocardial infarction in Argentina. Considering the 2010 census with 40.117.096 residents in Argentina [4] and estimating 10/10.000 the incidence of MI from previous studies, we calculated 800 cases, with alpha error of 0.05.

Multiple logistic regression analyses were performed for predictors of in-hospital outcomes. Variables included in the final multivariate models compromised those with a significance level <0.01 n the univariate analyses, unless otherwise stated. A statistical analysis was performed with STATA 9.0 (STATA Corporation, College Station, TX®).

3. Results

Seven hundred and fifty-eight patients were included, 476 (60.55%) with STEMI and 281(39.45%) non-STEMI. Demographics for the population are shown in Table 1.

Most patients (72.8%) arrived from their home, and 27.2% were referred from other hospitals for the following reasons: Hospital

Table 1

Demographic characteristics.

MI (all) STEMI

Age (median ± SD) 61.9 ± 12.4 61 ± 12.3

Male (%) 76.6 75

BMI (median ± SD) 27.9 ± 4.62 27.9 ± 4.62

Diabetes (%) 22.2 20

DBT on insulin (%) 14 11

Current smoker (%) 37.7 42

Former smoker (%) 24.1 22

Hypercholesterolemia (%) 43.3 51

Hypertension (%) 66.7 63

Chronic stable angina (%) 8.4 7

Myocardial infarction (%) 18.3 13

Percutaneous angioplasty (%) 14.7 10

CABG (%) 5.12 2

Heart failure (%) 5.25 3

Chronic pulmonary disease (%) 6.32 6.11

Unstable angina (%) 9.17 5

Stroke (%) 2.9 3

HIV (%) 2.11 1.3

Neoplasm (%) 4 2.9

Coronary obstruction >50% (%) 25 18%

Chronic renal failure (%) 3.78 2.36

Peptic ulcer (%) 2.86 3.24

Bleeding (%) 2.71 2.14

ASA/clopidogrel (%) 36 29

ACE/ARAII 41 39.3

Statins (%) 23.6 18

Beta-blockers (%) 31.6 25.2

Health insurance coverage (%)

-Uninsured 17 20

-OS 56 56

-Private insurance 27 24

complexity (16%), insurance coverage (3.95%), medical decision (2.24%), family decision (1.31%), other (1.03%). Although the median time from symptom onset to admission was 135 min (60-345), there was a mean delay of 242 min (120-510) when patients were referred from other institution.

Angina 24 h before the admission was present in 30.7% of patients, and the majority (80.7%) were on Killip class I on admission, while 8% were on Killip 3/4.

Sixty three percent received anticoagulation therapy, 99% non-STEMI and 36% STEMI (low molecular weight heparin in 58% of patients), for an average of three days (2-5 days). Ninety nine percent of patients were treated with aspirin, 86% with clopidogrel and 11% with prasugrel. Antiaggregation therapy was started in the ICU in 55% of patients, in the emergency department in 27%, immediately before PCI in 12%, and after PCI in 6%. The median loading dose of clopidogrel was 300 mg (IR 300-600) and the maintenance dose 75 mg Q.D.

The mean hospital stay was 5 days (4.5-7) and mean ICU stay was 4 days [3-5].

In-hospital mortality was 7.35%, 85% due to cardiac complications. The variables associated with mortality are shown in Table 2.

In a multivariate model, mortality was independently associated with age (OR 1.06, CI95 1.02-1.1, p = 0.001), moderate or severe left ventricular dysfunction (OR 7.12, CI95 2.5-20, p < 0.001), Killip 3-4 (OR 4.86, CI95 1.64-14,p = 0.004). Treatment with ACEi (OR 0.18, CI95 0.06-0.48, p < 0.005) and beta-blockers (OR 0.22, CI95 0.07-0.62, p = 0.05) were independently associated with lower in-hospital mortality.

STEMI was observed in 476 patients on admission. The demographic characteristics for these patients are shown in Table 1. Compared to non-STEMI, patients with STEMI were younger (p = 0.01), and prior hospitalization for UA or HF was more frequent in NSTEMI than in STEMI patients (15% vs. 5.6% for UA, p = 0.013; and 9 vs. 3%, for HF p = 0.01, respectively).

Table 2

Univariate analysis for mortality in MI.

OR (CI) p

Age 1.07 (1.05-1.1) < 0.001

Female 1.86 (1.03-3.3) 0.04

DBT 2.22 (1.24-3.98) 0.007

TBQ 0.47 (0.24-0.9) 0.024

DLP 0.9 (0.5-1.62) 0.72

HTA 2.23 (1.1-4.5) 0.026

CSA 1.84 (0.79-4.3) 0.16

UA 1.45 (0.59-3.56) 0.41

HF 5.82 (2.64-12.84) <0.001

LBBB 2.83 (1.12-7.17) 0.028

RBBB 3.98 (1.79-8.86) 0.001

CRF 3.79 (1.47-9.81) 0.006

Specular ST changes 2.6 (1.22-3.83) 0.009

ST elevation 1.36 (0.74-2.49) 0.32

SAP 0.98 (0.96-0.99) <0.001

DAP 0.95 (0.93-0.97) <0.001

KK 3.24 (2.5-4.2) <0.001

Right ventricular dysfunction 8.6 (3.7-19.7) <0.001

Glycemia on arrival 1.01 (1.003-1.09) <0.001

Fasting glycemia 1.01 (1.01-1.02) <0.001

Coronary angioplasty 0.59 (0.31-1.11) 0.1

Clopidogrel 0.70 (0.34-1.44) 0.33

Beta-blockers 0.06 (0.03-0.12) <0.001

Statins 0.09 (0.04-0.19) <0.001

ARE 0.1 (0.05-0.19) <0.001

Acute renal failure 6.82 (3.3-14) <0.01

Stroke 4.28 (1.14-16.1) 0.031

Major bleeding 2.15 (0.62-7.52) 0.23

Hypotension 12.26 (5.85-25.66) <0.001

The mean time from symptom onset to admission was 120 min (60-330) for patients arriving from home, and 240 min (120-510) for patients referred from another institutions.

285 patients underwent primary PCI with mean door-to-balloon time of 107 min (60-231) min; 92 patients received thrombolysis with mean time from symptom onset to admission 180 min (110250), mean door-to-needle time 55 min (29-90); 29 patients were treated with rescue PCI, 16 p with pharmacoinvasive-PCI and 2 by facilitated-PCI. The reasons for no reperfusion were: late presentation (34%), non-STEMI (29%), contraindication (1.5%), transitory ST elevation (12%), not reported (13%), others (10.5%).

Mortality (8%) was associated with time to reperfusion: door-to-balloon time less than 90 min for primary PCI was associated with a significant reduction in mortality ((OR 0.34, CI95 0.11-0.98), p = 0.04).

Twenty patients (2.6%) presented bleeding complications including 12 (60%) upper GI bleeding, 3 (15%) intracranial bleeding, 2 (10%)

epistaxis, 1 (5%) lower GI bleeding, 1(5%) hematuria, and 1(5%) hemoptysis.

Medication prescribed at discharged was aspirin in 99% of patients, dual antiplatelet therapy in 87%, ACEi in 81%, beta-blockers in 89% and statins in 95%.

For every year over 65 years of age there was a 7% increase in mortality, females had almost twice the risk for mortality than males (OR 1.86(1.03-3.33)), and a history of diabetes (OR2.2 (1.2-4)) and hypertension were associated to in-hospital death in a univariate analysis. Mortality was independently associated with age (OR 1.09, CI95 1.04-1.14, p < 0.001), Killip 3-4 (OR 3, CI95 1.24-12.8, p = 0.02), and inotrope requirement (OR 19, CI95 6-60, p < 0.001). Door-to-balloon time < 90 min for primary PCI (PPCI) was independently associated with a significant reduction in mortality (OR 0.11, CI0.01-0.68, p = 0.001) in STEMI.

Fifty-six per cent had OS, 27% had private insurance and 17% were uninsured patients. There were demographic differences between groups: patients with OS were older (62.9 ±12 year) than uninsured patients (57.4 ± 8 year) and patients with private insurance (60 ± 14 year), more patients were > 75 years old (21%, 3.2%,14.7% respectively), ANOVA 0.002 (p < 0.001 between OS and uninsured patients p = 0.07 between uninsured patients and patients with private insurance). Compared to uninsured patients and patients with private insurance, patients with OS had more diabetes (25% vs. 17% vs. 10%, respectively, ANOVA 0.004, p = 0.004 between OS and private insurance) and arterial hypertension (ANOVA 0.0008 (p = 0.002 between OS and uninsured patients and p = 0.03 between patients with private insurance and uninsured patients)).

Patients with OS had higher mortality. Patients with private insurance were treated with more invasive procedures(Table 3 and Fig. 1).

4. Discussion

The SCAR registry observed a 7.35% overall mortality for AMI and 8% for STEMI in Argentina, higher than the mortality described in Europe [5], the US [6] and developing countries [7]. The outcomes were affected by insurance coverage.

Baseline characteristics of the population did not differ significantly from other registries. We studied a younger population, and age is a strong predictor of mortality in acute coronary syndromes (ACS) [8]. Nevertheless, patients with OS were significantly older and had more diabetes, two conditions associated with mortality.

Ventricular dysfunction and hemodynamic instability have been associated with mortality in many other trials, and beta-blockers have demonstrated a reduction in mortality, reinfarction and sudden death after MI when they are appropriately prescribed in hemodynamic stabilized patients [9,10]. More than 80% of patients in the SCAR registry

Table 3

Differences in outcomes and procedures in patients with different insurance coverage.

Uninsured OS Private p

(17%) (55.8%) (26.8%)

Hospital mortality 6.3% 9.5% 2.6% ANOVA 0.0089 (*between OS and private p = 0.007)

Coronary angiography 35.8% 47% 58% ANOVA 0.0006 (*p < 0.001 between uninsured and private; p = 0.046 between OS and private)

Coronary angioplasty (total) 25.8% 39.7% 47.1% ANOVA 0.039 (p = 0.048 between uninsured and OS; p = 0.003 between uninsured and private)

Coronary angioplasty in non-STEMI 27.3% 54.8% 68.5% 0.002 (p = 0.044 between uninsured and OS; p = 0.002 between uninsured and private)

Reperfusion in STEMI 76.3% 79.7% 84.2% ANOVA 0.18

Primary angioplasty 56.3% 75.5% 92.6% ANOVA < 0.001 (p = 0.002 between uninsured and OS, p = 0.03 between OS and private, p < 0.001 between uninsured and private)

Hospital mortality in STEMI 4.3% 11.5% 2.8% 0.0089 (p = 0 between OS and private)

Fig. 1. Outcomes and procedures according to insurance coverage.

were on KK 1 or 2, and the treatment with beta-blockers exceeded 90% of patients at discharge.

So, how can we explain the higher mortality observed in SCAR?

Patient profile alone does not seem to explain differences in short-term clinical outcomes after MI [2,7,11,12]. The variation in rates of reperfusion therapies, and the delay in initiating specific treatments and socioeconomic variables might play a role. Many reports have described geographic variations in treatment patterns that could be related to outcomes [13,14]. Acute reperfusion therapy with either PPCIor fibrinolysis reduces mortality in eligible patients in STEMI [15]. Rates of reperfusion are improving in Europe [16] and the USA [6], but it is heterogeneous in other registries. In France, the overall rate of cardiovascular mortality among patients with STEMI decreased with the greater use of reperfusion therapy between 1995 and 2012 [17].

In the SCAR registry 79% of the patients received reperfusion therapy in STEMI (60% went to PPCI and 24% went to thrombolysis), compared to 64% and 14%, respectively, in the French registry [18]. We observed significant differences in the rate of PPCI and time to reperfusion according to insurance coverage.

The use of reperfusion therapy was not independently associated with mortality in the regression analysis, nevertheless, time to PPCI <90 min correlated to less mortality in STEMI, as it has been demonstrated in prior trials [19,20]. Although there is evidence that treatment delay is harmful for both PPCI and FL [21], SCAR did not find door-to-needle to be a significant predictor of mortality in a multivariate analysis. This can be related to the low number of patients included in this group.

However, the relative mortality benefit of PPCI over FL depends not only on hospital-based PCI-related delay, but also on patient characteristics and system delay (eg. location, weather and traffic) [22]. For example, differences in care-seeking behavior may be caused by cultural factors reflecting differences in interpretation of the signs and symptoms of acute coronary disease [23]. In the acute stage of MI, the use of invasive procedures could be related to the type of payer [24].

Nearly 30% of patients were referred from other hospitals in SCAR, with a longer delay to initiate treatment. We have no information, but it is possible that the choice of transfer destination might have been driven by the presence of supplemental insurance or corporate relationships between hospitals that refer and admit patients despite the potential benefit associated with transfer, as has been demonstrated previously by Iwashyna in Pennsylvania [25]. Even among patients

who do not require transfer for reperfusion, a substantial proportion often suffers needless delays from door to FL or PCI. Prior studies have shown that many patients who are transferred from hospitals without PCI capability to a PCI-capability institution experience long delays in treatment without a clear survival benefit [26-28]. In Argentina OSs have their own clinics or economic arrangements with private clinics where patients are usually transferred to receive specific treatments like coronary angioplasty. This could have resulted in long delays.

It is important to consider other factors. Wang et al. described dissociation between door-to-balloon time improvement and decrease in mortality, highlighting the importance of overall quality of care improvement for AMI [29]. It could be possible that single process measures are simple reflections of the entire care system organization and cultural and socioeconomic situation. No visible differences could contribute to the results, like equipment, personal training or type of stents used. In 2000, French laws extended the system of health coverage and designed a free full universal medical coverage insurance for low-income patients < 60 years of age. In this system, patients were admitted to the same types of institutions, including academic hospitals and private clinics and the use of cardiac catheterization and coronary interventions was similar. Probably that was the reason why inhospital mortality was also comparable. This should alert as to the translation of results between different countries around the word.

5. Limitations

The methods used to collect data for SCAR are subject to a number of recognized limitations that may hinder its ability to generalize the study findings to the entire country. Restriction of the registry to patients who were admitted may have resulted in the exclusion of patients dying early in the emergency room. Otherwise, it is a voluntary registry; as a result our survey included a high proportion of academic medical centers with revascularization facilities.

However, SCAR is the largest multicenter registry to include the complete spectrum of patients with ACS in Argentina.

6. Conclusions

Despite that mortality has decreased since 2005 [30], the SCAR registry shows that in-hospital mortality for AMI persists to be high in Argentina. Efforts to improve reperfusion rates and delay to treatment

are necessary, especially in STEMI. However we must consider other variables that might influence the mortality like care system organization and cultural and socioeconomic situation. Universal medical coverage doesn't seem to eliminate health inequalities when providing access to optimal care is not guaranteed. Coordinated intersectorial actions should be taken to ensure greater access to the best treatment in AMI.

Conflict of interest

Authors have no conflict of interest. References

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