Causes of Death in Patients Asking for Polyclinic Care for Coronary Heart Disease.

Aim: Retrospective analysis of the underlying causes for death of patients who did and did not seek outpatient medical care (OPMC) for ischemic heart disease (IHD), and discussion of a possibility for using administrative anonymized but individualized databases for analysis.
Material and Methods: The electronic database of the Central Administration of the Civil Registry Office of the Moscow Region (Unified State Register of the Civil Registry Office of the Moscow Region), including medical death certificates (MDC) for 2021, was used to select all cases of fatal outcomes with the disease codes of the International Classification of Diseases, Tenth Revision (ICD-10) (codes of external causes, injuries, poisonings excluded) that were indicated as the primary cause of death (PCD). Personalized data of the deceased were combined with data from electronic medical records of patients who sought OPMC at institutions of the Moscow Region within up to 2 years before death. In addition to IHD, the following PCD codes were taken into account: malignant tumors, COVID-19, diabetes mellitus, cerebrovascular diseases, hypertension, chronic obstructive pulmonary disease, alcohol-associated diseases, and, as examples of unspecified PCD, old age and unspecified encephalopathy.Results In total, among those who died from diseases, the proportion of those who died from IHD was 18.9%; for another 8.4%, IHD was indicated as a comorbid disease in Part II of the MDC. Among those who sought OPMC for IHD, the IHD proportion indicated as PCD was 27.5%, and among those who did not seek OPMC 17.4% (p <0.0001). Those who died from IHD and who had sought OPMC were older (mean age, 75.59 ± 10.94 years) than those who died from IHD and had not sought OMPM (mean age, 73.96 ± 10.94 years; p < 0.0001). The frequency of myocardial infarction as PCD among those who had and had not sought OPMC was the same (12%), chronic forms of IHD were 83.9% and 79.7%, the frequencies of "unspecified" acute forms of IHD (codes I24.8-9) were 4.1% and 8.3%, respectively. The proportion of deaths from COVID-19 was the highest (21.7% and 24.3%, respectively), from malignant neoplasms 11.6% and 12.7%, respectively, and from unspecified encephalopathy 10.6% and 10.7%, respectively.
Conclusion: Only 25% of patients who had sought OPMC for IHD died from IHD, otherwise the causes of death were the same as for patients who had not sought OPMC for IHD. Analysis of administrative databases allows identifying disparities in the PCD structure and to direct the efforts of specialists to reconciling the criteria for death from various forms of IHD.