Introduction
Cardiovascular diseases (CVD) are highly prevalent and the leading cause of death in many parts of the world. Common CVD are myocardial infarction (MI), stroke, heart failure (HF), and atrial fibrillation (AF). These frequently occur together and reciprocally increase the risk of each other.
Methods
We analysed the occurrence of CVD in 89,975 participants of eight population-based cohorts of the MORGAM project carried out in six European countries. Hazard ratios were calculated for the onset of a second CVD event after the diagnosis of the first ever CVD event and depending on the time since diagnosis of the first CVD. Simultaneous co-occurence was defined as the onset of two or more CVD events within 30 days, for this analysis we excluded cases in which death occured on the same day as a CVD event.
Results
During the median follow-up of 13.9 years, a total of 6,008 individuals developed an MI (6.7%), 5,398 individuals HF (6.0%), 4,430 individuals AF (4.9%) and 3,866 individuals a stroke (4.3%). The cluster of MI and HF was most frequent (1,761 individuals), followed by HF and AF (1,667 individuals), MI and stroke (788 indivdiuals) and AF and stroke (740 individuals). 114 individuals developed all four CVDs.
Simultaneous co-occurence of CVD was found in 340 individuals with MI and HF, in 325 individuals with HF and AF, in 125 individuals with stroke and AF, and in 116 individuals with MI and AF. Co-occurence of both MI and HF with stroke was less likely to appear within 30 days (69 and 38 indivdiuals, respectively).
The risk of developing HF after AF was highest (hazard ratio (HR) 8.03, 95% confidence interval (CI) 6.32 - 10.19, p-value <0.01), followed by the risk of developing HF after MI (HR 7.84, 95% CI 6.54 - 9.39, p-value <0.01) and the risk of developing AF after HF (HR 6.62, 95% CI 4.91 - 8.91, p-value <0.01). The HRs for any other combination of CVD were lower, ranging from 1.49 to 2.14. The risk increase after the occurrence of one CVD was particularly pronounced in the first year after diagnosis and decreased afterwards, with an HR of up to 18.42 (95% CI 15.31 - 22.16 <0.01) for HF in the first years after a MI.
Conclusions
CVDs are common in the general population and frequently occur in clusters. The risk for developing a second CVD largely varies, and is highest for HF after AF, followed by HF after MI. This risk is highest in the first year after the initial diagnosis and decreases afterwards. These findings highlight the need for tailored aftercare after a CVD diagnosis.
