The Evolving Epidemiology of Infective Endocarditis: An Observational Study from Western India

Background

Over the last few decades, the epidemiology and the management of infective endocarditis (IE) is undergoing significant evolution and advancements respectively. Many studies from the developed world and some from India have brought this to light.

Objective

To study demography, risk factors, microbiological spectrum, clinical profile, management, and outcome of IE in a tertiary care setup in western India.

Materials and Methods: This is a retrospective observational study of 90 patients diagnosed with definite as well as possible IE and admitted to the intensive care units (ICU) and wards in our institute from April 2015 to May 2022. Demographics, signs and symptoms, laboratory results, echocardiography, radiological findings, treatment, and outcomes were studied.

Results

73 (81.1%) were definite and 17 (18.9%) were possible cases of IE. 93.3% cases were community-acquired, 6.7% were hospital acquired. Mean age of the patients was 43.3 + or - 18.8 years. Male: female ratio was 4.3:1. 62.2% had an underlying cardiac illness, with congenital heart disease (CHD) being the most common (18.9%) followed by rheumatic heart disease (RHD) (16.5%). Fever, weight loss, dyspnea, and cough were the common presenting symptoms. 69 (76.7 %) patients had native valve IE, 13 (14.4%) had prosthetic valve IE, 6 (6.7%) had vegetations on the endothelium without involvement of the valves, 2 (2.2%) patients had vegetations on the prosthetic material used for repair of congenital heart defects. About 48% of patients had a history of prior receipt of antibiotics. Blood cultures were positive in 48 (53.3%) patients. Most common valve infected was the mitral valve (MV) and the most common organisms isolated were the viridans group of streptococci (VGS), with penicillin (Pn) MIC <0.5 mcg/ml of all but one isolate. Transesophageal echocardiography (TEE), done in 17 patients, improved the pick-up of abnormal echo findings from 83.3% to 91.1%. Ceftriaxone was the most common antibiotic used. Surgery was done in 22 (24.4%) patients. 67 (74.4%) patients were cured, 14 (15.6%) patients died and 9 (10%) patients were lost to follow-up.

Conclusion

The increasing age of patients, absence of any underlying cardiac ailment, the importance of TEE in patients with high suspicion of IE, and the trend towards early surgery were the important aspects highlighted with respect to the changes happening in the field of IE. Almost all the strains of VGS, the most common isolated organisms, retained their sensitivity to Pn and ceftriaxone, making the treatment possible with once-a-day dosing of ceftriaxone monotherapy, highlighting the utilization of outpatient antibiotic therapy (OPAT).