SNOWMASS, COLO. – Infective endocarditis in 2019 is very different from the disease most physicians encountered in training, both in terms of epidemiology and clinical presentation, Patrick T. O’Gara, MD, observed at the Annual Cardiovascular Conference at Snowmass sponsored by the American College of Cardiology.
The classic description of infective endocarditis provided by Sir William Osler, MD, was of a subacute bacterial infection characterized by a long latent phase of low-grade fever, back pain, weight loss, and night sweats. It was mainly a right-heart disease of younger individuals with an infected native valve, and the predominant pathogens were streptococci, Dr. O’Gara said.
“I think in the current era endocarditis is more often characterized by an acute illness with toxic features in the context of adults with a high burden of degenerative diseases – for example, patients with rheumatoid arthritis or psoriatic arthritis on immunosuppressive therapy, or diabetes, end-stage renal disease, and risk factors for hospital-acquired infection. Injectable drug use is through the roof, there’s a wider prevalence of cardiac implanted electronic devices, which are a wonderful place for bacteria to hide, and Staphylococcus aureus has certainly become the leading pathogen with regard to endocarditis in the United States, especially MRSA, often multidrug resistant,” said Dr. O’Gara, professor of medicine at Harvard Medical School, Boston.
“Also, no talk about endocarditis is sufficient without paying some attention to the opioid crisis in which we find ourselves. It’s one of the top three causes of death among young men in the United States, along with accidents and gun violence. No region of the country is spared. This has completely inundated our ER and hospitalist services and our inpatient cardiology services with folks who are often repeat offenders when it comes to the difficulty in being able to give up an injectable drug use habit. They have multiple infections and hospitalizations, tricuspid valve involvement, and depending upon the aggressiveness of the Staphylococcus organism, typically they have left-sided disease with multiple complications, including aortic regurgitation and heart failure,” the cardiologist continued.
This description underscored one of Dr. O’Gara’s major points about the challenges posed by infective endocarditis in contemporary practice: “Expect the unexpected,” he advised. “When you’ve seen one case of infective endocarditis, you’ve seen one case of infective endocarditis.”
Outcomes are ‘sobering’
In the current era, outcomes are “sobering,” the cardiologist noted. Infective endocarditis carries a 6-month mortality rate of 20%-25% despite early surgery being performed during the index hospitalization in up to 60% of patients, with a relatively high perioperative mortality rate of about 10%. However, the risk of reinfection occurring in a newly implanted cardiac valve is impressively low at about 2%.
Refer early for multimodality imaging and surgical consultation
Transesophageal echocardiography is valuable in assessment of the infected valve. However, when extravalvular extension of the infection is suspected and the echo assessment is nondiagnostic or indeterminate, it’s time to quickly move on to advanced imaging, such as PET-CT.