[Chronic obstructive pulmonary disease and cardiovascular risk]

Lack of association of ischemic heart disease with COPD when taking into account classical cardiovascular risk factors

The aim of our study is to determine whether chronic obstructive pulmonary disease (COPD) is an independent risk factor for ischemic heart disease and whether this association is related with a greater prevalence of classical cardiovascular risk factors. Ours is a case-control cross-sectional study design. Cases were hospital patients with ischemic heart disease in stable phase, compared with control hospital patients. All patients underwent post-bronchodilator (PBD) spirometry, a standardized questionnaire, and blood analysis. COPD was defined as per GOLD PBD forced expiratory volume in the first second (FEV₁)/forced vital capacity (FVC) < 0.70. In our series of patient cases (n = 204) and controls (n = 100), there were 169 men in the case group (83%) and 84 in the control group (84%). Ages were 67 and 64 years, respectively (P < 0.05). There were no significant differences by weight, body mass index (BMI), packyears, leukocytes, or homocysteine. The abdominal perimeter was significantly greater in cases (mean 101 cm ± standard deviation [SD] 10 versus 96 cm ± 11; P < 0.000). Both groups also had significant differences by C-reactive protein (CRP), fibrinogen, and hemoglobin values. In univariate analysis, increased risks for cases to show with individual classical cardiovascular risk factors were seen, with odds ratio (OR) 1.86 and 95% confidence interval (CI) (1.04–3.33) for diabetes mellitus, dyslipidemia (OR 2.10, 95% CI: 1.29–3.42), arterial hypertension (OR 2.47, 95% CI: 1.51–4.05), and increased abdominal perimeter (OR 1.71, 95% CI: 1.06–2.78). Percent predicted PBD FEV₁ was 97.6% ± 23% in the patient group and 104% ± 19% in the control group (P = 0.01), but the prevalence of COPD was 24.1% in cases and 21% in controls. Therefore, COPD was not associated with ischemic heart disease: at the crude level (OR 1.19, 95% CI: 0.67–2.13) or after adjustment (OR 1.14, 95% CI:0.57–2.29). In conclusion, COPD was not associated with ischemic heart disease. The greater prevalence of classical cardiovascular risk factors in COPD patients could explain the higher occurrence of ischemic heart disease in these patients.

[Calculation of morbidity, use of resources and costs of patients treated with tiotropium bromide for COPD in a Spanish population]

OBJECTIVE

To determine the co-morbidity and economic impact of treatment with tiotropium bromide (TB) for COPD, in a population cared for by Spanish primary care teams (PCTs) and specialist physicians, in the context of routine clinical practice.

DESIGN

Retrospective multi-centre study.

SETTING

Four PCTs and 2 urban hospitals.

PARTICIPANTS

Patients with COPD receiving regular treatment with TB, during 2004.

MAIN MEASUREMENTS

Age and sex, episodes of co-morbidity, clinical parameters, resource use, and pharmacological groups. The costs model was established by differentiating semi-fixed from variable costs (pharmacy, tests, referrals) in the PCTs, as well as the visits, emergencies and hospital admissions occurring in the hospitals. A logistical regression analysis was made to correct the model. The costs were contrasted by analysis of covariance (ANCOVA), with the estimation of marginal means (Bonferroni adjustment).

RESULTS

Of 900 patients with COPD, 14.3% (n=129) received treatment with TB (95% CI, 12.0%-16.6%). The mean episodes/patient/year was 2.1 (1.4) versus 1.8 (1.3) (NS), seriousness/severity 41.3% versus 26.3% (P =.001), defined daily dose (DDD) 5928.5 (9624.1) versus 6187.7 (12471.3) (NS) and number visits/patient/year 15.1 (9.4) versus 17.3(11.9) (P=.044). After adjustments for age and sex, TB use was associated with Diabetes Mellitus (OR=1.6; 95% CI, 1.0-2.5; P=.034) and severity of patients' illness (OR=1.8; 95% CI, 1.2-2.8; P=.004). Quantification of unit cost/year was 2793.16 (3166.30) euros (3359.27 [3423.25] euros versus 2703.09 [3113.75] euros; P=.001). The adjusted patient cost/year was 2831.23 euros (SE, 217.32) with TB versus 2786.86 euros (SE, 88.53) without TB (NS).

CONCLUSIONS

TB is associated, as therapy complementing routine treatment, with the presence of Diabetes, and with the severity of the disease. The costs of COPD entail high resource consumption. The prescription of TB does not imply greater overall cost of the disease.