In a recent study published within the Journal of The American Heart Association, researchers assess trends in infective endocarditis (IE)-associated deaths in the USA from 1999 to 2020.

Study: Trends in Infective Endocarditis Mortality in the USA: 1999 to 2020: A Cause for Alarm. Image Credit: SquareMotion / Shutterstock.com

What’s IE?

IE is a severe heart disease with a high morbidity and death rate. Despite an increase in IE-associated hospital admissions within the U.S., in-hospital deaths have been declining globally. Nevertheless, age-standardized mortality rates remain regular.

The U.S. is currently experiencing the biggest opioid epidemic in history, with injection drug usage (IDU) being a major consequence. The standard IE epidemiology within the U.S. has modified on account of the opioid crisis, with younger, healthy individuals becoming more susceptible.

Studies on IE trends amongst U.S. adults are limited and typically only include hospital results. There’s also limited information on the national-level implications of opioid surge on IE-associated mortality.

In regards to the study

In the current nationwide cross‐sectional study, researchers examine national- and state-level trends in IE-associated mortality amongst U.S. residents 15 years of age and older. Mortality differences by age, race, sex, and geography amongst U.S. residents were also evaluated using data obtained from death certificates and associations of IE with substance use.

The U.S. Centers for Disease Control and Prevention’s Wide‐Ranging Online Data for Epidemiologic Research (CDC WONDER) multiple causes of death (MCOD) data were analyzed between 1999 and 2020. IE and substance use were identified from the International Classification of Diseases, tenth revision, and clinical modification (ICD-10-CM) codes.

The Vital Statistics Cooperative receives death certificate data from 57 vital statistics authorities within the U.S. The CDC National Center for Health Statistics (NCHCS) compiles the MCOD statistics.

National- and state-level crude death rates amongst individuals aged between 15-24, 25-34, 35-44, 45-54, 55-64, 65-74, 75-84 years, and 85 years and older were also obtained. Mortality rates with IE because the underlying explanation for death (UCOD) and IE with substance usage disorders as comorbid conditions were compared between 1999-2006, 2007-2013, and 2013-2020. Age‐adjusted mortality rates (AAMR) trends were examined by log‐linear regression modeling, and the typical annual percent change (AAPC) values were calculated.

Study findings

IE‐associated AAMRs within the U.S. were reduced from 26.2 for each a million individuals in 1999 to 22.4 for each a million in 2020. A statistically significant reduction in age-adjusted IE-associated AAMRs was observed between 1999 and 2020.

Between 1999 and 2004, there was a non-significant increase in AAMR, followed by significant decreases until 2020. Of all reported IE fatalities, 84 had immunodeficiencies, 10,803 were diabetic, and 9,911 had chronic renal disease.

Period cohort study findings showed that the relative risk was the least for people born around 1960 and increased for cohorts born after 1960, which led to a 2.3-point relative risk within the 1990 cohort. Nevertheless, IE-associated crude deaths rose significantly amongst individuals aged between 25 and 34 years and people between 35 and 44 years of age, with AAPC values of 5.4 and a pair of.3, respectively.

IE-associated crude deaths remained stable amongst individuals aged between 45 and 54 years of age but significantly reduced amongst individuals 55 years of age and older. Kentucky, West Virginia, and Tennessee were related to accelerated age‐adjusted death rates as in comparison with other U.S. states with predominantly reducing or static trends. Individuals between 25-34 and 35-44 years of age died at the next rate, with IE and substance usage disorders reported as comorbidities.

State-level trends with IE and drug use as comorbidities were related to the best AAMR values for Kentucky, Tennessee, and West Virginia. IE-associated AAMRs reduced from 25 for each a million in 1999 to twenty for each a million in 2020 amongst women, yielding an AAPC value of 1. Significant reductions in IE‐associated AAMRs were observed amongst males from 28 for each a million in 1999 to 26 for each a million in 2020, yielding an AAPC value of 0.6.

IE-associated AAMR significantly decreased amongst black and white individuals, along with Pacific Islander and Asian individuals. IE‐associated AAMR reduced amongst Hispanic individuals from 18 for each a million in 1999 to 12 for each a million individuals in 2020, thus yielding an AAPC value of 1.30. IE‐associated AAMR amongst non‐Hispanic individuals reduced from 27 for each a million in 1999 to 24 for each a million in 2020, yielding an AAPC value of 0.6.

Conclusions

While age-adjusted death rates for IE have decreased, there was a major increase in mortality amongst individuals between 25 and 44 years of age, particularly in states like Tennessee, West Virginia, and Kentucky.

The increases in IE-related mortality could also be on account of the opioid crisis, which has disproportionately affected young adults. Further research is required to know the causes of rising IE-related mortality and the impact of harm reduction initiatives on IE epidemiology.