Study explores changes in cardiovascular disease hospitalization trends during the COVID-19 pandemic

By Vijay Kumar MalesuReviewed by Sophia CoveneyAug 10 2023

In a recent study published in Scientific Reports, a group of researchers examined the variations in cardiovascular disease (CVD) hospital diagnoses in the Netherlands during the coronavirus disease 2019 (COVID-19) pandemic compared to the pre-pandemic period.

The study revealed significant declines in several CVD incidences but a notable increase in pulmonary embolism (PE).

Background

During the COVID-19 pandemic, global and national reports showed an increase in excess mortality, which is the death rate beyond expected norms. In the Netherlands, there were about 30,000 excess deaths between 2020 and 2021, with 341,508 total deaths. Initially, all excess deaths were directly attributed to COVID-19. By late 2021, only 70% of excess deaths were due to the virus.

While the direct effects of COVID-19 include increased rates of venous thromboembolism (VTE) and other cardiovascular issues in hospitalized and non-hospitalized patients, the indirect impact has been profound, causing healthcare delays and lifestyle changes. Hence, it is important to comprehensively analyze the distribution of non-COVID-19-related diseases during the COVID-19 pandemic.

This will help unveil possibly overlooked issues and prepare for the imminent disease burden. Although decreased diagnoses of some non-COVID-19 diseases, like cerebrovascular events, have been reported by some studies, research on the pandemic's influence on cardiovascular diseases in clinical settings remains limited.

About the study

In the present study, data from the entire Dutch population was utilized, which comprised household income, personal details, mortality rates, and hospital diagnosis data, with more information detailed in supplementary sections.

The primary focus was on cardiovascular disease diagnoses made during hospital stays, referencing a list of various cardiovascular conditions identified through the international classification of diseases (tenth revision, ICD-10) codes. Additionally, the research aimed to outline the 2020 hospitalization trends, particularly concerning COVID-19.

For data analysis, weekly diagnosis rates of cardiovascular diseases were established, with the 2015-2019 data modeling expected 2020 rates if the pandemic had not occurred. Poisson regression models factored in demographics like age, sex, income, and immigration background.

Incidence Rate Ratios (IRRs) for 2020 vs. 2019 were determined using Poisson regression and considering patient profiles and medical history. A comorbidity index was developed to adjust for various health conditions. R software facilitated data analysis, leveraging multiple specialized packages. Finally, sensitivity analyses were conducted, focusing on primary hospital diagnoses and excluding imputed diagnoses.

Study results

The present study assessed the personal characteristics of individuals during the initial phase of the COVID-19 pandemic in the Netherlands in 2020 and juxtaposed this data against 2019 figures. In 2020, the study encompassed 17,376,087 people, with an average age of 42.3 years, 50.3% being female. Most participants were of Dutch origin (75.7%), and 9.7% had a comorbidity index of 1 or higher.

From 2015 to 2020, hospital records showed fluctuating VTE incidence rates, including PE and Deep Vein Thrombosis (DVT). There was a notable uptick in VTE rates during the first COVID-19 wave in 2020.

Although these rates initially dipped to pre-pandemic levels, a second surge occurred during the pandemic's second wave. The predominant factor in this surge was a rise in PE hospital diagnoses. Meanwhile, DVT rates in 2020 paralleled those of previous years.

Records from 2020 revealed a decrease in ischemic stroke cases during the pandemic's first wave, which eventually returned to regular levels. A sharp drop in myocardial infarction cases was recorded during the first wave, though these rates rebounded post the initial wave.

The occurrence of transient ischemic attack (TIA) and other arterial thromboembolic events also decreased during the first COVID-19 wave and remained lower throughout the year.

There were recorded weekly incidence rates of atrial fibrillation, heart failure, and other relevant conditions from 2015 to 2020. A drop in incidence was observed for several conditions during the pandemic’s first wave when compared to 2019. These rates typically reverted to normalcy by the second wave.

When comparing expected versus actual weekly incidence rates for various cardiovascular diseases in 2020, the patterns largely mirrored those from 2015-2019. Upon narrowing the analysis to primary hospital admissions, VTE’s incidence rate during the first wave of the pandemic decreased by 21%. However, during the pandemic’s second wave, VTE rates were similar to those in 2019. The incidence rate for PE admissions also dropped by 20% during the first wave. Yet, this rate equaled the 2019 figures during the second wave.

Conversely, the initial analysis suggested a higher VTE rate during 2020, primarily influenced by PE, than in 2019. For DVT as a primary diagnosis, the first wave’s incidence rate plunged by 36% compared to 2019. This contrasted the initial analysis, which aligned the DVT rate with 2019 figures. When focusing only on unimputed diagnoses, the findings were consistent across all outcomes.

Conclusions

To summarize, the present study results indicated an uptick in hospital diagnoses for VTE, primarily PE, during both waves of the pandemic in contrast to 2019. Conversely, diagnoses of conditions like ischemic stroke, myocardial infarction, and heart failure saw a decline during the first wave when compared to the prior year.

Potential reasons for these trends could be patients’ reluctance to seek care during the pandemic, leading to decreased consultations. Studies indicate that 20% of Dutch participants avoided medical care during the pandemic’s first wave, even when experiencing severe symptoms.

Another factor could be physicians' hesitation to refer patients to emergency rooms due to limited resources and infection risks. The elevated VTE incidents, mainly due to PE, during the pandemic have potential long-term implications, as a significant portion of PE survivors could develop post-pulmonary embolism syndrome.