gms | German Medical Science

Background: Cardiovascular diseases are the leading cause of death in Germany. The objective of this study was to gain a better understanding of real-world patients with coronary artery disease (CAD) and/or peripheral artery disease (PAD) in terms of the epidemiology of the disease, clinical characteristics of patients, treatment patterns, and the incidence of related complications.

Materials and methods: We conducted a cohort study based on the InGef database between 2011 and 2016. The database consists of anonymized data from ca. 7.2 million insured members of more than 60 statutory health insurances in Germany. For the analysis of the data, a sample of about 4 million insurants was used which is representative to the German population in terms of age and sex. Two cohorts were defined: a population-based cohort, in which the prevalence and incidence of CAD and/or PAD was calculated, and a disease-specific cohort, in which enrolled subjects with incident CAD and/or PAD were described regarding demographic (age, sex, year of cohort entry) and clinical characteristics (incidence of complications, comorbidities, and treatment patterns). Inclusion criteria for the population-based cohort were age ≥18 years and continuous insurance of at least two years. Index date for cohort entry was 01 January 2013. The inclusion criteria for the disease-specific cohort were the same plus an incident diagnosis of CAD and/or PAD between 2013 and 2015. Patients with a diagnosis in 2011 or 2012 as well as patients with a coronary artery bypass grafting or a percutaneous coronary intervention before the index diagnosis were excluded. CAD was defined via ICD-10 GM codes I20–I25 either by primary hospital diagnosis or by verified ambulatory or secondary hospital diagnosis in at least two different quarters. PAD was defined via ICD-10 GM code I70.2 using the same criteria for diagnosis. Prevalence and incidence rates were calculated for the years 2013–2015. Clinical characteristics for the disease-specific cohort included typical comorbidities such as chronic obstructive pulmonary disease (COPD), heart failure or diabetes, as well as complications such as amputation, gastrointestinal bleeding or hemorrhagic stroke, and treatment patterns, where the proportion of patients treated with antiplatelets and anticoagulants within six months after diagnosis as well as the distribution of the prescribing physician specialty was investigated.

Results: The population-based cohort included 3,444,266 insurants. In the disease-specific cohort, there were 61,793 patients with CAD (mean age 66.5±12.8 years, 41.5% female, 58.5% male), 12,711 patients with PAD (mean age 69.1±11.6 years, 41.8% female, 58.2% male), and 12,294 patients with both CAD and PAD (mean age 73.4±10.0 years, 31.8% female, 68.2% male). The pooled prevalence for CAD in 2013–2015 was 8.3% (95% confidence interval (95%CI): 8.2%–8.3%). For PAD, the pooled prevalence was 1.4% (95% CI: 1.4%–1.4%) and for both CAD and PAD 0.8% (95%CI: 0.8%–0.8%). The incidence rate per 10,000 person-years was 87.6 (95%CI: 86.9–88.2) for CAD, while the incidence rate for PAD was 90.5 (95%CI: 89.3–91.6). The combination of both CAD and PAD showed the lowest incidence rate per 10,000 person-years (15.3 (95%CI: 15.0–15.6)). Regarding comorbidities, the most common in all patient groups was hypertension (71.4% in patients with CAD, 74.6% in patients with PAD, and 92.1% in patients with both CAD and PAD). Likewise, COPD was most common in patients with both CAD and PAD (30.1%), followed by patients with PAD (18.5%) and CAD (14.5%). The same pattern was also found for diabetes, which was prevalent in 53.0% of patients with CAD and PAD, in 37.7% of patients in PAD, and in 14.5% of patients with CAD. Heart failure was found in 12.5% of patients with CAD, 12.6% in patients with PAD, and in 36.1% of patients with both CAD and PAD. The most common complications for patients with CAD were percutaneous coronary interventions and myocardial infarctions, with 958 and 575 incident cases per 10,000 person-years respectively, while the most common complication for patients with PAD was percutaneous transluminal angioplasty (1,366/10,000 person-years). This complication was also most common for patients suffering from both CAD and PAD (1,205/10,000 person-years). The mortality rate was highest in patients with both CAD and PAD (1,188 deaths per 10,000 person-years), followed by patients with PAD (703/10,000 person-years) and CAD (452/10,000 person-years). In terms of treatment patterns, 39.7% of CAD-patients initiated treatment with antiplatelets and 9.5% with anticoagulants within 6 months after incident diagnosis. For patients with CAD-related hospitalization, the proportion for antiplatelets was slightly higher (50.6%) and slightly lower for anticoagulants (8.1%). For patients with PAD, 31.9% initiated antiplatelet-treatment and 5.8% anticoagulant-treatment, while 35.0% and 9.9% of patients with both CAD and PAD initiated treatment with antiplatelets and anticoagulants, respectively. In a sensitivity analysis, we additionally calculated the proportion of patients hospitalized with myocardial infarction who initiated antiplatelet and anticoagulant treatment within 6 months: here, the proportions were 75.8% and 9.2%, respectively. For all patients, treatment was almost exclusively initiated by general practitioners.

Conclusion: Despite a high disease burden and high incidence of complications, patients with CAD, PAD, and both CAD and PAD might receive insufficient treatment with antiplatelets; a drug class, which is recommended for CAD and PAD patients by the German treatment guidelines. Further studies are warranted to investigate factors associated with treatment initiation of antiplatelets and adherence of antiplatelet treatment.

Conflict of interest: The study and abstract were performed on behalf of Bayer Vital GmbH.