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ORIGINAL ARTICLE

Cardiology Journal 2008, Vol. 15, No. 5, pp. 451–457 Copyright © 2008 Via Medica ISSN 1897–5593

In-hospital management and mortality in elderly patients with non-ST-segment elevation acute coronary syndromes treated in centers without on-site invasive facilities Artur Dziewierz 1, Zbigniew Siudak 1, Tomasz Rakowski 1, Joanna Zdzienicka 1, Dominika Dykla 1, Waldemar Mielecki 1, Jacek S. Dubiel 1, Dariusz Dudek 2 1 2

2 nd Department of Cardiology, Jagiellonian University Medical College, Krakow, Poland

Department of Interventional Cardiology, Jagiellonian University Medical College, Krakow, Poland

Abstract Background: The purpose was to assess age-related differences in hospital management and mortality in non-ST-elevation acute coronary syndrome (NSTE ACS) patients treated conservatively, with a focus on the influence of aggressive pharmacological treatment on in-hospital clinical outcome. Methods: We identified 807 NSTE ACS patients treated conservatively in the 29 hospitals participating in the Krakow Registry of Acute Coronary Syndromes from February to March 2005 and from December 2005 to January 2006. Out of 807 patients’ 32.1% were less than 65 years of age, 33% from 65 to 74, 30.5% from 75 to 84, and 5.3% ≥ 85. For all patients, pharmacotherapy index based on the use of pharmacological treatment regimen during hospital stay was assessed. Each patient received 1 point for each of the following guideline-recommended drugs used: aspirin, clopidogrel, glycoprotein IIb/IIIa inhibitor, LMWH, beta-blocker, ACE inhibitor/angiotensin II receptor blocker and statin — the range of points being from 0 to 7. Results: Significant age-related differences in baseline characteristics and pharmacotherapy index values were found. In-hospital mortality was higher in elderly patients (2.4% vs. 3.4% vs. 8.9% vs. 14.0%, respectively for age groups, p < 0.0001). Similarly, in non-shock patients and in patients with elevated cardiac markers, age-dependent differences in mortality were observed. Independent predictors of in-hospital death were: age, cardiogenic shock, elevated cardiac markers and pharmacotherapy index. Conclusions: Advanced age is associated with less aggressive pharmacological treatment and higher in-hospital mortality in NSTE ACS patients remaining in community hospitals for conservative treatment. Broader implementation of current guidelines and more frequent invasive treatment might improve the outcomes of NSTE ACS patients regardless of age. (Cardiol J 2008; 15: 451–457) Key words: acute coronary syndrome, elderly, management, mortality

Address for correspondence: Dariusz Dudek, MD, PhD, Department of Interventional Cardiology, Jagiellonian University Medical College, Kopernika 17, 31–501 Kraków, Poland, tel: +48 12 424 71 81, fax: +48 12 424 71 84, e-mail: [email protected] Received: 4.08.2008

Accepted: 26.08.2008

www.cardiologyjournal.org

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Cardiology Journal 2008, Vol. 15, No. 5

Introduction Age is a strong predictor of adverse events in patients with non-ST-elevation acute coronary syndromes (NSTE ACS) [1–4]. Also, age obviously affects the choice of acute pharmacological therapy, as well as the application of invasive treatment [3, 4]. As the number of elderly NSTE ACS patients is progressively increasing, the assessment of the safety and efficacy of aggressive invasive strategy and adjunctive therapies in elderly patients is an issue of increasing importance. Unfortunately, it must be emphasized that elderly NSTE ACS patients are often excluded from randomized clinical trials and it is hard to generalize expected outcomes from trials to the real life setting for the elderly. More reliable data concerning actual treatment strategies and outcomes in elderly NSTE ACS patients may be drawn from large scale, multicentre registries [3]. The purpose of the present study was to assess age-related differences in management and mortality in NSTE ACS patients treated in hospitals without on-site invasive facilities, with a focus on the influence of aggressive pharmacological treatment on in-hospital clinical outcome.

Methods The Krakow Registry of Acute Coronary Syndromes is a prospective, multicentre, observational registry designed to examine current epidemiology, in-hospital management and outcome of patients with acute coronary syndromes in this region of Poland (Krakow, Malopolska) [5, 6]. A total of 29 community hospitals without on-site invasive facilities participated in the registry during two study periods: from February 2005 to March 2005 and from December 2005 to January 2006 (two separate patient enrolment periods). To minimize selection bias, all consecutive patients with a suspected diagnosis of acute coronary syndrome were included regardless of the treatment strategy or outcome. During the index hospitalization, data concerning baseline demographic and clinical characteristics, relevant laboratory results, pharmacotherapy during hospital stay and adverse cardiovascular outcomes were recorded on a standardized, electronic, web page-based case report form (https:// //www.cardio.pl/acs/index.php). Standardized definitions were used for adverse events and final diagnosis. Data were collected in a central electronic database. This database was reviewed for completeness by an independent physician, and site

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queries were generated if needed. For all patients, pharmacotherapy index based on the use of pharmacological treatment regimen during hospital stay was assessed. Each patient received 1 point for each of the following guideline-recommended drugs used: aspirin, clopidogrel, glycoprotein IIb/IIIa inhibitor, low-molecular-weight heparin, beta-blocker, angiotensin-converting enzyme inhibitor/angiotensin II receptor blocker and statin — the range of points being from 0 to 7 [6]. Contraindications to the use of each medication were not analyzed. Cardiogenic shock was defined as reduced blood pressure (systolic blood pressure < 90 mm Hg or a drop of mean arterial pressure > 30 mm Hg) and/ /or low urine output (< 0.5 mL/kg/h), with a pulse rate > 60 beats per minute with or without evidence of organ congestion [7]. The primary end point was in-hospital mortality. Occurrence of other ischemic and bleeding events was not analyzed. For the purpose of this analysis, the patients were divided into four pre-specified age groups (< 65, 65 to 74, 75 to 84 and ≥ 85 years of age).

Statistical analysis Values were expressed as mean ± standard deviation or medians (interquartile range). Categorical variables were presented as percentages. Statistical comparisons between age groups were performed using the chi-square test and Fisher’s exact test for categorical variables and Kruskal-Wallis test for continuous variables, as appropriate. In addition, multivariate Cox regression analysis was performed to find significant predictors of in-hospital death. Risk of in-hospital death was expressed as odds ratios with 95% confidence intervals. All tests were 2-tailed, and a p value of < 0.05 was considered statistically significant.

Results The Krakow Registry of Acute Coronary Syndromes database included 1414 patients with acute coronary syndrome admitted between February 2005 and March 2005, and between December 2005 and January 2006. A total of 435 (30.9%) patients with final diagnosis other than NSTE ACS (e.g. ST-segment elevation myocardial infarction, stable angina, extracardiac cause of chest pain) were excluded from the analysis. Out of the remaining 979 patients, a total of 172 (17.6%) were transferred for invasive treatment and 807 (82.4%) patients were treated conservatively without invasive approach during index hospital stay — the studied group (Fig. 1).


Artur Dziewierz et al., Management and mortality in elderly NSTE ACS patients

Figure 1. Scheme of group distribution in the registry.

Out of 807 patients treated conservatively, 252 (32.1%) patients were < 65 years of age, 266 (33%) from 65 to 74, 246 (30.5%) from 75 to 84, and 43 (5.3%) ≥ 85 years of age (Fig. 1). Baseline demographic and clinical characteristics of this group of patients according to age are shown in Table 1. Twenty-two (2.7%) patients were in cardiogenic shock and 226 (33.0%) had elevated cardiac markers. There was a prevalence of male gender, diabetes mellitus, arterial hypertension, hyperlipidemia, prior angina, prior myocardial infarction, prior revascularization, current smoking, peripheral arterial disease, history of renal failure, and time from symptoms onset to admission, as well as heart rate and diastolic blood pressure on admission was significantly dependent on age. Elderly patients were more likely to have had elevated serum cardiac markers and to have been in cardiogenic shock on admission. Mean left ventricular ejection fraction was significantly lower among elderly. Pharmacological treatment during hospital stay, according to age, is shown in Table 2. Elderly patients were less likely to receive clopidogrel, beta-blockers or statins during index hospital stay. Usage of aspirin, glycoprotein IIb/IIIa inhibitors and angiotensin-converting enzyme inhibitor/angiotensin II receptor blockers were similar among the different age groups. Mean pharmacotherapy index was 4.3 ± 1.1 points. Pharmacotherapy index values differed significantly between the age groups. For patients < 65 years of age vs. 65 to 74 years of

age vs. 75 to 84 years of age vs. ≥ 85 years of age mean pharmacotherapy indices were 4.4 ± 1.1 vs. 4.3 ± 1.1 vs. 4.2 ± 1.1 vs. 3.9 ± 1.4 points, respectively (p = 0.044). Similarly, in non-shock patients (4.4 ± 1.1 vs. 4.3 ± 1.1 vs. 4.2 ± 1.0 vs. 4.0 ± 1.3 points, respectively, p = 0.168) and in patients with elevated cardiac markers (4.4 ± 1.1 vs. 4.2 ± 1.4 vs. 3.9 ± 1.3 vs. 3.3 ± 1.5 points, respectively, p = = 0.095) pharmacotherapy index values were lower in elderly patients. Total in-hospital mortality was 5.3%. In patients with cardiogenic shock, in-hospital mortality rates were 54.5% vs. 3.9% for non-shock patients (p < 0.0001). Similarly, in-hospital mortality was higher in patients with elevated cardiac markers than in patients without elevated cardiac markers (18.6% vs. 2.5%, p < 0.0001). In-hospital mortality rates were higher in elderly patients than their younger counterparts (for patients < 65 years of age vs. 65 to 74 years of age vs. 75 to 84 years of age vs. ≥ 85 years of age: 2.4% vs. 3.4% vs. 8.9% vs. 14.0%, respectively, p < 0.0001). Similarly in non-shock patients (7.4% vs. 3.0% vs. 31.4% vs. 42.9%, respectively, p = 0.001) and in patients with elevated cardiac markers (1.6% vs. 2.7% vs. 5.9% vs. 15.0%, respectively, p = 0.001) an age-dependent difference in mortality was observed. In-hospital mortality stratified by pharmacotherapy index values for consecutive age groups is shown in Figure 2. In multivariate Cox regression analysis, independent predictors of in-hospital death were age, cardiogenic


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Table 1. Baseline demographic and clinical characteristics stratified by age. Values are presented as percentages or medians (interquartile range). Variable

Age (years) < 65 (N = 252)

65–74 (N = 266)

75–84 (N = 246)

≥ 85 (N = 43)

69.0

52.6

41.9

37.2

Male Body mass index [kg/m2]

P

26.5 27.3 26.2 26.9 (24.4–29.7) (24.5–30.1) (24.2–28.7) (24.4–29.7)

Diabetes mellitus

< 0.0001 0.119

4.8

11.3

13.0

14.0

0.004

Arterial hypertension

76.2

87.2

83.3

74.4

0.006

Hyperlipidemia

68.3

60.5

53.3

41.9

< 0.0001

Prior angina

69.8

79.7

82.9

76.7

0.004

Prior myocardial infarction

31.3

33.5

42.7

39.5

0.043

Prior heart failure symptoms

9.5

25.2

35.0

48.8

< 0.0001

Prior percutaneous coronary intervention

11.9

9.0

6.1

4.7

0.116

Prior coronary artery bypass graft

4.0

9.4

2.8

0.0

0.003

Prior stroke/transient ischemic attack

3.6

4.1

7.3

7.0

0.185

Current smoker

41.7

24.4

12.2

4.7

< 0.0001

Family history of coronary artery disease

0.195

16.7

13.5

10.2

11.6

Peripheral arterial disease

4.4

8.3

11.0

9.3

0.039

Renal insufficiency

2.0

3.8

10.6

7.0

< 0.0001

Chronic obstructive pulmonary disease

7.5

10.2

13.0

14.0

0.180

Chest pain on admission

59.1

65.8

57.3

48.8

0.080

Time from chest pain onset to admission [h]

7 (2.5–20)

9 (4–20)

7 (3–16)

12 (5–24)

0.007

Heart rate on admission [beat/min]

75 (65–90)

77.5 (70–90)

80 (70–100)

90 (78–100)

< 0.0001

Systolic blood pressure on admission [mm Hg]

140 (130–160)

150 (130–160)

142.5 (129–160)

135 (130–160)

0.189

Diastolic blood pressure on admission [mm Hg]

90 (80–100)

90 (80–100)

80 (80–90)

85 (80–90)

0.045

35.1

47.6

51.4

62.5

0.038

ST-segment deviation ≥ 2 anginal events in last 24 hours

32.4

30.6

35.5

43.8

0.701

Elevated serum cardiac markers

24.3

26.6

47.7

43.8

0.001

TIMI risk score 0 to 2 points

53.8

19.5

13.6

14.0


41.2

56.1

60.2

62.8


5.0

24.4

26.2

23.2

Cardiogenic shock on admission

1.2

2.3

4.1

7.0

0.056

60 (52–65)

56 (46–62)

55 (42–62)

53 (47–60)

< 0.0001

Left ventricular ejection fraction (%)

< 0.0001

TIMI — Thrombolysis In Myocardial Infarction

shock, elevated cardiac markers and pharmacotherapy index (Table 3).

Discussion As we have shown previously, cardiogenic shock, renal insufficiency, thrombolysis in myocardial infarction (TIMI) risk score and pharmacotherapy index were independent predictors of in-hospital death in NSTE ACS patients treated conservatively

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during index hospital stay [6]. These findings are confirmed by current analysis. Regardless of the risk profile (age, cardiogenic shock, elevated cardiac markers) pharmacotherapy index was shown to be an independent predictor of in-hospital death. Importantly, for every unit increase in the pharmacotherapy index, the risk of in-hospital death decreased by 56%. Also, observed age-related difference in aggressiveness of pharmacological treatment may be one of the explanations of higher in-hospital mortality in elderly NSTE ACS patients.



Table 2. Pharmacological treatment during hospital stay stratified by age. Values are presented as percentages. Variable

Age (years)

P

< 65 (N = 252)

65–74 (N = 266)

75–84 (N = 246)

≥ 85 (N = 43)

Aspirin

95.2

95.5

93.9

95.3

0.864

Clopidogrel

13.9

9.8

6.1

9.3

0.034

Ticlopidine

21.8

20.3

17.9

7.0

0.127 0.479

Glycoprotein IIb/IIIa inhibitor

4.0

3.0

2.0

0.0

Low-molecular-weight heparin

68.3

74.4

78.9

74.4

0.062

Beta-blocker

86.5

84.6

80.5

67.4

0.011

Angiotensin-converting enzyme inhibitor/ /angiotensin II receptor blocker

78.6

77.4

74.4

72.1

0.615

Calcium antagonist

14.3

16.2

7.3

4.7

0.006

Nitrates

69.0

79.3

70.3

65.1

0.023

Statins

89.7

83.8

82.1

69.8

0.004

Fibrates

1.2

0.4

0.8

0.0

0.666

Figure 2. In-hospital mortality stratified by age and pharmacotherapy index values.

Table 3. Multivariate Cox regression analysis for in-hospital death. Variable

Odds ratio

95% confidence interval

P

Gender (male)

1.60

0.72–3.60

0.252

Age (per 1 year)

1.04

1.00–1.09

0.034

Cardiogenic shock

4.16

1.59–10.92

0.004

Elevated cardiac markers

4.30

1.52–12.17

0.006

Pharmacotherapy index (per 1 point)

0.56

0.42–0.74

< 0.001

Similarly to previous studies, higher prevalence of female gender, diabetes mellitus, arterial hypertension, prior angina, prior myocardial infarction, prior revascularization, peripheral arterial disease, and history of chronic renal failure in elderly NSTE ACS patients were observed [3]. Comorbid conditions are associated with a worsening of long-term clinical outcome of NSTE ACS patients. For exam-

ple, impaired renal function is an independent predictor of higher mortality in acute coronary patients [8, 9]. Previous studies have shown that elevated serum cardiac markers and the presence of cardiogenic shock on admission are strong predictors of worse clinical outcome in NSTE ACS patients [1, 2, 10]; in the studied patients, they were more frequently observed in elderly subjects, but,


455


importantly, their effect on mortality was age-independent. Time from chest pain onset to admission was also longer in the elderly, and in elderly patients, a trend toward presentation without chest pain was observed. We have shown recently that atypical symptoms, including lack of chest pain, are associated with less aggressive pharmacological and invasive treatment of NSTE ACS patients and higher in-hospital mortality, especially in patients with elevated serum cardiac markers [11]. Because adherence to guidelines is associated with better patient outcome, high-risk patients with NSTE ACS should receive treatment that most closely adheres to guidelines. Paradoxically, high-risk groups identified in CRUSADE (Can Rapid Risk Stratification of Unstable Angina Patients Suppress Adverse Outcomes with Early Implementation of the ACC/AHA Guidelines) include the elderly, women, patients with diabetes, patients with congestive heart failure, and patients with elevated serum troponin levels that were undertreated and were less likely to receive guideline-recommended therapies including invasive diagnostics and invasive treatment [12–14]. Importantly, the CRUSADE registry data demonstrated that patients who present with NSTE ACS and do not receive guidelinerecommended therapies have a higher mortality rate [12, 13]. Mean pharmacotherapy index values were lower among elderly patients, mainly as a result of lower frequency of clopidogrel, beta-blockers and statin usage during index hospital stay. Glycoprotein IIb/IIIa inhibitors usage rate was low, but similar among age groups. On the other hand, nowadays use of glycoprotein IIb/IIIa inhibitors in conservative treatment of NSTE ACS is rather controversial [15, 16]. The influence of pharmacotherapy index on in-hospital mortality was independent of age. These findings are in line with the study by Alexander et al. [4], which showed a correlation between in-hospital mortality and the number of guideline recommendations applied (cardiac catheterization, short-term aspirin, short-term beta-blocker, short-term heparin and short-term glycoprotein IIb/ /IIIa inhibitors) in NSTE ACS patients. Significantly, the correlation was observed in patients ≥ 75 years of age, as well as those < 75 years of age [4]. The present study has a number of limitations. First, it has all the limitations of a registry. Secondly, the usage of pharmacological therapies was not randomized. Patients were not screened for other contraindications, and strict indications for the use

456

of each medication and the appropriateness of the used dosage were not assessed. It is very likely that in some patients various therapies were not used due to important clinical reasons. Risk assessment and the occurrence of bleeding complications were not implemented into the model. More importantly, bleeding complications form an important side effect causing mortality. In a real life situation, the fear of bleeding complications is certainly an issue which would be significant enough to include in the algorithm of treatment. In addition, probably the relative weight of each drug on outcome is not equal in the studied population. Usage of diverse grading scale for each treatment could be justified. For that reason, to address the potential limitations of confounding biases, we used multivariable Cox analysis to control the influence of baseline characteristics and risk profiles on in-hospital mortality. Thirdly, the study focused only on in-hospital clinical outcomes of patients with NSTE ACS. Data concerning long-term clinical follow-up for this group of patients was not available. In the presented registry of consecutive NSTE ACS patients, less than 20% of patients were transferred for invasive diagnostics and treatment during index hospital stay. We expect that in this medically treated cohort there were a lot of patients who would have benefited from an invasive strategy, especially in the intermediate-to-high-risk patient population including elderly subjects [12, 13]. Despite substantially increased risk of angiographic percutaneous coronary intervention complications, death and bleeding events in elderly patients compared with their younger counterparts, the studies emphasized that older patients who underwent aggressive revascularization therapies vs. conservative management had greater absolute risk reductions of mortality and other ischemic events than younger patients [17–19]. In conclusion, advanced age is associated with less aggressive pharmacological treatment and higher in-hospital mortality in NSTE ACS patients remaining in community hospitals for conservative treatment. Broader implementation of current guidelines and higher rates of invasive treatment could improve the outcome of NSTE ACS patients, regardless of age.

Acknowledgements The authors do not report any conflict of interest regarding this work.



Occluded coronaries for Cardiogenic shocK? J Am Coll Cardiol,

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