Summary
Background
Elderly patients with an acute coronary syndrome (ACS) are less likely to be enrolled into randomized, controlled trials or receive guideline-recommended therapies, because of a higher burden of comorbidity, including functional decline.
Aim
To assess the prognostic value of functional decline in a prospective, observational cohort of elderly ACS patients.
Methods
ACS patients aged ≥ 70 years were enrolled. The ACS definition included ST- and non-ST-segment elevation myocardial infarction, and unstable angina pectoris. Clinical admission and laboratory data and echocardiographic variables were recorded. Functional decline was defined as needing assisted care in daily life. The study endpoint was all-cause mortality.
Results
Overall, 151 patients were enrolled (mean age 78 ± 5 years; 52% men). Twenty-eight (19%) patients had functional decline. No significant difference in therapeutic management was observed between patients with functional decline and those living independently. Twenty-seven (18%) patients died during follow-up (median 447 days). Functional decline correlated with poor outcome ( p = 0.008; hazard ratio [HR] 2.87 [1.31–6.25]). Other prognostic markers were diabetes, Killip class ≥ II, elevated E/Ea ratio, C-reactive protein, B-type natriuretic peptide, haemoglobin, glycaemia and no coronary angiography. By multivariable analysis, C-reactive protein > 13 mg/L correlated with poor outcome ( p = 0.007; HR 4.77 [1.52–14.96]). There was a trend towards correlation between functional decline and poor outcome ( p = 0.051; HR = 2.77 [0.99–7.72]).
Conclusion
Functional decline seems to portend poor prognosis in elderly ACS patients. Larger, community-based studies are needed to confirm these findings in a multivariable model.
Résumé
Introduction
Cette étude a pour but d’évaluer l’impact pronostique de la perte d’autonomie chez des sujets âgés de plus de 70 ans hospitalisés pour un syndrome coronaire aigu (SCA).
Méthode
Cent cinquante et un patients de plus de 70 ans hospitalisés pour un SCA ont été inclus. L’ensemble des données cliniques, biologiques et échocardiographiques du patient a été recueilli prospectivement. La perte d’autonomie était définie par la nécessité d’un recours à une ou des aides extérieures dans la vie quotidienne. Le critère principal était le décès toutes causes confondues.
Résultats
L’âge moyen était de 78 ± 5 années avec 52 % d’homme. La perte d’autonomie était constatée chez 28 patients (19 %). Aucune différence significative de thérapeutique n’a été mise en évidence entre les deux populations (avec ou sans perte d’autonomie). Vingt-sept patients (18 %) sont morts durant un suivi moyen de 447 jours. La perte d’autonomie ressort comme un facteur de mauvais pronostic de manière significative ( p = 0,008 ; HR 2,87 [1,31–6,25]). Les autres marqueurs pronostiques mis en évidence sont le diabète ( p = 0,016 ; HR 2,57 [1,19–5,54]), le stade Killip supérieur ou égal à 2 ( p = 0,008 ; HR 2,89 [1,32–6,31]), l’élévation du rapport E/Ea ( p = 0,025 ; HR 1,07 [1,01–1,13]), ainsi que des marqueurs biologiques tels que la C-reactive protein ( p < 0,0001 ; HR 1,85 [1,37–2,51]), le B-type natriuretic peptide ( p = 0,023 ; HR 1,41 [1,05–1,91]), le taux d’hémoglobine ( p = 0,002 ; HR 0,73 [0,60–0,89]), la glycémie ( p = 0,012 ; HR 2,95 [1,27–6,82]), et l’absence de coronarographie ( p = 0,012 ; HR 1,62 [1,19–1,82]). En analyse multivariée, un taux de C-reactive protein supérieur à 13 mg/L émerge comme facteur pronostique indépendant ( p = 0,007 ; HR = 4,77 [1,52–14,96]). Une tendance à la limite de la significativité est observée dans l’association entre perte d’autonomie et mortalité ( p = 0,051 ; HR = 2,77 [0,99–7,72]).
Conclusion
La perte d’autonomie semble donc être un facteur de mauvais pronostic chez les sujets âgés présentant un SCA. Cependant, une plus large étude sera nécessaire pour valider ces résultats préliminaires et les intégrer dans un modèle multivarié.
Introduction
Ageing is a major risk factor for ACS and is also associated with worse prognosis . However, because of a higher burden of comorbid conditions, including functional decline, elderly patients who present with an ACS are enrolled much less frequently into randomized, controlled trials and are less likely to receive guideline-recommended therapies . Accordingly, we aimed to evaluate whether functional decline correlates with outcome in older people (aged ≥ 70 years) presenting with an ACS. In addition, we studied whether functional decline impacts on ACS therapeutic management in daily clinical practice.
Methods
Population
The study cohort consisted of ACS patients (≥ 70 years) who were admitted to the cardiac intensive care unit of the Centre Hospitalier Régional et Universitaire de Lille. Elderly patients with non-ST-segment elevation and ST-segment elevation ACS according to the European Society of Cardiology guidelines were included in the study. Elderly ACS patients in cardiac arrest or with cardiogenic shock requiring mechanical ventilation ( n = 12), severe primary cardiac valvular disease ( n = 39), Takotsubo syndrome ( n = 9) or normal coronary angiograms despite elevated cardiac troponin ( n = 4), were ineligible for the study.
Clinical data
Medical history, admission heart rate, systolic blood pressure, Killip classification, medications and laboratory tests (including glucose level [normal 65–100 mg/dL] and haemoglobin [normal 13–18 g/dL for men, 12–16 g/dL for women]) performed on admission were recorded. Clinical data included age, sex, history of smoking, documented diagnosis of hypertension (patients receiving antihypertensive medications or having known, but untreated, hypertension [blood pressure ≥ 140/90 mmHg]), hypercholesterolaemia (patients on cholesterol-lowering medication or in the absence of such medication, low-density lipoprotein cholesterol level > 160 mg/dL) and diabetes (fasting blood glucose level > 126 mg/dL on two occasions or patients currently receiving oral hypoglycaemic medication or insulin). Body mass index was calculated as weight (kg)/height 2 (m 2 ). Activity level was assessed systematically using the Katz Basic Activities of Daily Living questionnaire . On the first day of admission, patients were asked about feeding, bathing, continence, dressing, toileting and transferring. Functional status was classified as functional decline (needing assisted care for at least one of the basic activities mentioned above) or as living independently. Electrocardiographic findings on admission were classified according to the presence or absence of ST-segment elevation. Cardiac troponin I levels were measured using the ADVIA Centaur TnI-Ultra assay (Siemens Healthcare Diagnostics Inc., Tarrytown, NY, USA) with a 99th percentile upper reference limit for cardiac troponin of < 0.05 ng/L. Plasma levels of B-type natriuretic peptide were measured using the ACS:180 BNP assay (Bayer ® ) (normal ≤ 100 pg/mL). C-reactive protein levels were measured using a turbidimetric immunoassay (normal < 4 mg/L). The glomerular filtration rate (normal ≥ 60 mL/min/1.73 m 2 ) was estimated using the four-component Modification of Diet in Renal Disease equation, incorporating age, race, sex and serum creatinine level: estimated glomerular filtration rate = 186 × (serum creatinine level in mg/dL) – 1.154 × (age in years) – 0.203. For women, the product of this equation was multiplied by a correction factor of 0.742 . At hospital discharge, echocardiograms were carried out by staff cardiologists using the HP SONOS 5500 ultrasound system (Philips, Andover, MA, USA) with a 2–4 MHz transducer. Left ventricular ejection fraction, tissue Doppler-derived diastolic function and mitral regurgitation were assessed as described previously .
Patient follow-up
After hospital discharge, the vital status of patients were monitored by telephone calls to referring cardiologists and primary care physicians, and by review of medical records. The primary endpoint of the study was death from all causes.
Statistical analysis
Continuous variables are expressed as means ± standard deviations or medians [25th–75th percentiles], as appropriate. Categorical variables are presented as absolute numbers and percentages. B-type natriuretic peptide and C-reactive protein were log-transformed to remove skewness of data distribution. Comparisons between groups were made using Student’s t test or the Mann-Whitney U test, as appropriate. Categorical variables were compared using the chi-square test or Fisher’s exact test, as appropriate. Event-free survival curves were constructed using the Kaplan-Meier method and compared using the log-rank test. Threshold values for biological variables were obtained using receiver operating characteristic curve analysis. Given the low number of events with regard to the univariate predictors of poor outcome, a Cox stepwise forward multivariable analysis was performed, with entry and retention set at 0.05. A two-tailed type I error rate < 0.05 was considered for statistical significance. Analyses were conducted using SPSS 13.0 (Chicago, IL, USA) and the SAS System Version 9.0 for Windows ® (SAS Institute, Cary, NC, USA).
Results
Patient characteristics
Between 01 January and 31 December 2007, 151 patients aged ≥ 70 years presenting with an ACS were enrolled in this study. There were 79 (52%) men and 72 (48%) women; the mean age was 78 ± 5 years. Clinical and echocardiographic characteristics at admission are shown in Table 1 . Forty-eight (32%) patients had ST-segment elevation ACS. History of coronary artery disease was reported in 31 (20%) patients and history of stroke in 23 (15%) patients. Twenty-three (15%) patients had a history of cancer. The use of glycoprotein IIb/IIIa receptor blockers was 15%, the use of clopidogrel was 77% and the use of aspirin was 94%. Percutaneous coronary interventions with stenting were performed in 99 (65%) patients.
| Variables | |
|---|---|
| Age (years) | 78 ± 5 |
| Aged 70–75 years | 47 (31) |
| Aged 75–80 years | 37 (24) |
| Aged 80–90 years | 67 (44) |
| Men | 79 (52) |
| Body mass index (kg/m 2 ) | 26 ± 5 |
| Hypertension | 122 (81) |
| Diabetes | 56 (37) |
| Current smoker | 12 (8) |
| Dyslipidaemia | 67 (44) |
| Heart rate (beats/min) | 81 ± 22 |
| Systolic blood pressure (mmHg) | 143 ± 31 |
| Killip class II IV | 59 (39) |
| ST-segment elevation | 48 (32) |
| Laboratory data | |
| Glomerular filtration rate (mL/min/1.73 m 2 ) | 61 [57–65] |
| C-reactive protein (mg/L) | 9.6 [5–26] |
| B-type natriuretic peptide (pg/mL) | 205 [90–465] |
| Glycaemia (mg/dL) | 137 [112–191] |
| Haemoglobin (g/dL) | 11.6 [10.3–13.1] |
| Echocardiography | |
| Left ventricular ejection fraction (%) | 48 ± 13 |
| Mild or severe mitral regurgitation | 4 (3) |
| E/Ea ratio | 13.2 ± 6.7 |
| Therapy on admission | |
| Aspirin | 62 (41) |
| Clopidogrel | 37 (24) |
| Beta-blocker | 61 (40) |
| ACE inhibitor/angiotensin II antagonist | 98 (65) |
| Aldosterone antagonist | 6 (4) |
| Statin | 67 (44) |
| Coronary angiography | 106 (70) |
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