Has the Diagnosis & Treatment of Endocarditis became Easier?
In recent decades, mortality and morbidity have diminished due to the use of bactericidal antibiotics at high doses, early valve replacement if this were necessary but especially thanks to an early diagnosis (improvement in blood culture technique and transthoracic and transesophageal echocardiography). Echocardiography is a test that uses sound waves to create images of the heart. An echocardiogram shows the heart while it beats; it also shows the heart valves and other structures. In some cases, the lungs, ribs, or body tissues can prevent sound waves and echoes from supplying a clear picture of cardiac activity. If this is a problem, the healthcare provider may inject a small amount of fluid (contrast material) through an intravenous line to better see the inside of the heart.
The transesophageal echocardiography is used to obtain a clearer echocardiographic image of the heart. The provider may use this test for signs of infection (endocarditis) or blood clots (thrombus).
When there are factors that predispose to a poor prognosis, the cure rates are lower. Factors of poor prognosis are:
- The development of heart failure, which is the most important factor.
- The non-streptococcal etiology, especially gram-negative or fungal infections.
- Involvement of the aortic or multivalvular valve.
- The infection of a prosthetic valve.
- Myocardial abscesses or valvular annulus.
- Advanced age
- Renal failure
- The endocarditis with negative cultures.
- The delay in the initiation of the treatment.
The defervescence usually occurs 3 to 7 days after antibiotic treatment, in most cases apyrexia (the absence of fever) is the main criterion of response to treatment, the appearance or persistence of fever raises several diagnostic possibilities:
- Drug fever
- Phlebitis in relation to the administration of antibiotics
- Extracardiac abscess
- Persistence of sepsis.
During the treatment periodical blood cultures should be taken, which usually become negative several days after the start of treatment. If fever and bacteremia persist, the formation of myocardial abscesses or metastases (usually associated with Staphylococcus aureus) should be suspected, however the most frequent cause of persistent or recurrent fever during treatment is a drug reaction, and to a lesser extent, the embolisms.
It may take several weeks after finishing the treatment before observing the increase in weight and elevation of hemoglobin (it is a protein in the body responsible for carrying oxygen and giving color to red blood cells. His work in the blood is of the utmost importance, responsible for carrying oxygen, through the lungs, to all tissues involved in the blood and respiratory systems).
During effective antimicrobial treatment and up to several weeks later, petechiae (they are small lesions of red color, formed by extravasation of a small number of erythrocytes when a capillary is damaged), Osler’s nodules (purple skin lesions, slightly elevated and located on the pulp of the fingers and toes, usually accompanied by local pain) and embolisms may appear.
Anticoagulation is not indicated in the treatment of endocarditis, since it did not foresee the separation of small fragments from the valvular thrombus, on the contrary it can increase hemorrhagic complications (especially intracranial).
The vast majority of relapses are detected by blood cultures, 2-4 weeks after stopping treatment. The recurrence rate is 0.3-2.5 / 100 patients per year, around 60% of patients will need to be operated on (20-30% in the initial stages and 30-40% at 5-8 years); patients who are discharged from hospital have a survival of 75-80% at 5 years. Approximately 10% of patients will suffer new episodes of endocarditis, months or years later. The prognosis of endocarditis on the early prosthetic valve is much worse than in the late form.