Clinical course and features of the diagnosis of infectious endocarditis in the elderly

Introduction

Infectious endocarditis (IE) can be suspected in a variety of clinical situations. This disease can manifest itself both as an acute, rapidly progressing infection, and as a subacute disease with a subfebrile temperature and nonspecific symptoms that can mislead or make it difficult to establish a diagnosis [1]. Without timely and proper treatment, IE leads to serious damage to the heart or even death. Therefore, early diagnosis and effective complex therapy are crucial for successful treatment [2–3].

Close attention to the relevance of this problem is paid by national and international medical associations, which in the published versions of clinical recommendations commented in sufficient detail on the main issues of diagnosis and therapy of IE, as well as its complications [3].

In this study, approaches to IE treatment and diagnosis are considered, taking into account the data covered in the recommendations of the European Society of Cardiology (ESC) in 2015, as well as in national clinical guidelines [4–5].

The most vulnerable age group for the development of IE is currently the elderly people. The problem of IE in this age group is relevant, since clinical manifestations have a number of features that complicate early diagnosis due to the presence of pathogens characteristic of the elderly, which involves the search and use of appropriate antibacterial drugs, the presence of concomitant diseases that complicate the choice of medications and cardiac surgery.

The relevance of IE in elderly patients also lies in the fact that the disease often manifests itself with atypical signs and symptoms. Among the clinical manifestations of IE, new aspects of damage to the heart (endocardium, myocardium), lungs, kidneys, and central nervous system are currently attracting special attention due to the high frequency of involvement of these organs in the pathological process [1].

The classical course of IE in most cases provides primarily conservative treatment with the use of massive and prolonged antibiotic therapy with bactericidal drugs (penicillin G, ampicillin, ceftriaxone, gentamicin, vancomycin, etc.). However, these tactics were also applied in this clinical case, but the diagnosis was not immediately established, which increased the time before effective antibacterial therapy was carried out, which contributed to the development of multi-valvular heart damage and led to the need for surgical treatment.

Description of the clinical case

Patient M., 73 years old, in April 2018, for no apparent reason, began to notice an increase in body temperature up to 39 °C, accompanied by chills, a feeling of chilliness, night sweats, interruptions in the work of the heart, swelling of the shins and feet. In her case, hyperthermia was combined with an increase in blood pressure to 140–150/80 mm Hg. The patient associated her condition with an acute respiratory viral infection and was treated independently with antipyretic medicines, she took Captopril with an increase in blood pressure, but the condition did not improve, and therefore in June she applied to a therapist at her place of residence. From anamnesis: in March 2018, she suffered from pneumonia.

In order to verify the diagnosis, a number of studies were conducted: a general blood test (June 5, 2018), which revealed normochromic anemia of mild severity (Hb — 96 g/l, erythrocytes — 3.6), leukocytosis (11.0), a neutrophilic shift to the left (banded neutrophile 14, segmentonuclear neutrophils 34), and acceleration of the sedimentation rate of erythrocytes up to 47 mm/h. During electrocardiography dated April 7, 2018, ventricular extrasystole and left ventricular myocardial hypertrophy were detected. The chest X-ray was performed (June 7, 2018) in order to exclude inflammatory diseases of the lungs and pleura: fluid was detected in the pleural sinuses during an ultrasound examination of the pleural cavities (left side — up to 200 ml of fluid, right side – up to 1600 ml). The ultrasound of the abdominal cavity dated June 7, 2018 showed signs of minor stagnation in the liver. The ultrasound of the pelvic organs showed no pathology.

Due to the presence of bilateral hydrothorax, according to radiography and ultrasound, the patient was hospitalized in June 2018 in the pulmonology department of the city hospital, where she was hospitalized for the period from June 12, 2018 to June 28, 2018. The oncological process of the right lung was not excluded. Since the presence of fever was noted, antibacterial therapy with Vancomycin, Amikacin, as well as expectorants and diuretics, was carried out. A cytological examination of the pleural fluid was carried out on June 19, 2018, in which no atypical cells were detected, and oncopathology was excluded. On June 21, 2018, the patient was consulted by a rheumatologist for the purpose of differential diagnosis with systemic connective tissue diseases; studies of antinuclear factor, rheumatoid factor, and antistreptolysin-O titer were conducted as well, according to the results of which diseases of this group were excluded. During auscultation of the heart, there was an apical systolic murmur, but it was regarded as a sign of relative mitral valve insufficiency against the background of aortic atherosclerosis.

After the treatment, hyperthermia was not observed in the patient, but the clinical picture in the form of interruptions in the work of the heart remained. In addition, shortness of breath appeared with little physical exertion, pallor of the skin, pain in the joints of the hands, and weight loss were noted. In this connection, on August 15, 2018, she was examined by a cardiologist. An objective medical examination revealed the following: during auscultation, heart tones were muted, the rhythm was correct; there was an apical systolic murmur, radiating into the left axillary region, at the Botkin-Erb’s point, diastolic noise in the aorta, the blood pressure was 120/50 mm Hg. An echocardiography examination was scheduled for August 17, 2018. As a result, the following was found: valvulitis of the aortic valve (vegetation of 5–12×3 mm) and mitral valves (floating vegetation of 16×6 mm and smaller) with the development of aortic valve insufficiency with regurgitation of the 3^rd degree and mitral valve insufficiency with regurgitation of the 3^rd-4^th degree. Dilation of the left chambers of the heart and right atrium were detected, as well as minor left ventricular myocardial hypertrophy, small hydropericardium, and bilateral hydrothorax.

The patient also underwent Holter monitoring (dated August 22–23, 2018): sinus rhythm, polytopic ventricular, and atrial extrasystole were detected.

On August 27, 2018, a bacteriological blood test was performed: a three-time study revealed Staphylococcus aureus.

On August 28, 2018, computed tomography of the chest was performed, as a result, the following conclusion was obtained: bilateral hydrothorax (medium — right side, small — left side), infiltrative changes in the lungs of nonspecific etiology, fibrous changes in the upper lobe of the left lung, moderate cardiomegaly, calcification of the aortic valve and coronary arteries, moderate arterial pulmonary hypertension, and small hydropericardium.

In connection with possible subsequent surgical treatment in September 2018, the patient was hospitalized in the cardiology department of the regional hospital, where a coronary angiography was performed on September 17, 2018. The following results were obtained: left type of myocardial blood supply; trunk of the left coronary artery — calcification; anterior descending artery — calcification, stenosis of the proximal and middle third up to 70%; envelope artery — uneven contours, right coronary artery — stenosis of the middle third up to 50%. The ultrasound of the brachiocephalic arteries was performed, which showed non-stenotic atherosclerotic changes in the brachiocephalic arteries.

During hospitalization, pleural punctures were performed three times on the right side; a total of 1600 ml of straw-yellow liquid was evacuated.

According to the results of the medical examination, the patient was diagnosed with “Primary infectious endocarditis caused by Staphylococcus aureus, subacute course. Valvulitis of the aortic valve (vegetation of 5–12×3 mm) and mitral valves (floating vegetation of 16×6 mm and smaller) with the development of aortic valve insufficiency with regurgitation of grade 3 and mitral valve insufficiency with regurgitation of the 3^rd–4^th degree. Atherosclerosis of brachiocephalic arteries without hemodynamically significant stenoses. Coronary atherosclerosis: stenosis of the proximal and middle third of the left anterior descending artery up to 70%, stenosis of the middle third of the left anterior descending artery up to 50%. Hypertension (stage II), controlled arterial hypertension. Left ventricular myocardial hypertrophy. The risk is very high. CHF IIA (III FC). Bilateral hydrothorax. Anemia of mild severity”.

Antibacterial therapy was prescribed: Oxacillin (12 g per day in 4 injections), hypotensive therapy, and correction of symptoms of heart failure (Bisoprolol, Spironolactone, Furosemide, Torasemide).

Against the background of the treatment, body temperature normalized, shortness of breath, and swelling of the lower extremities decreased. Blood was seeded three times for sterility on September 25–27, 2018; the growth of microflora was not detected. The patient was discharged with a referral for hospitalization to the Federal State Budgetary Institution “National Medical Research Center named after V. A. Almazov” of the Ministry of Health of Russia, where surgical treatment was performed on October 17, 2018, namely prosthetics of the aortic (Neo-Cor 21 mm) and mitral valve with a biological prosthesis (Neo-Cor 28 mm). When opening the right pleura, 500 ml of transudate was evacuated, 1000 ml was evacuated from the left pleura. An open oval window with a diameter of 6 mm was found. Mitral valve: scalloped, partially destroyed by an infectious process, loose cherry-colored vegetation on the cusps. Aortic valve: the valve was tricuspid, the body of the right coronary flap was destroyed, a long mobile vegetation was found on the left coronary flap. A histological examination confirmed the diagnosis of “Subacute infectious endocarditis of the aortic and mitral valves without necrosis and shadows of microbial colonies with vascularization and lymph-plasmocytic infiltration, hemosiderophages, vegetation from fibrin on AV”. The postoperative period proceeded with moderate cardiovascular insufficiency. No effusion in the pericardial cavity was detected during the control of echocardiography.

Clinical case discussions

The course of IE is characterized by a significant variety, thereby complicating its diagnosis; therefore, in approximately 40% of patients with infectious heart disease, the disease is recognized late. The average period of diagnosis is 50–90 days, and with IE of the right chambers of the heart, it can exceed it [6–7]. In 32% of cases, when a patient was admitted to a hospital, IE was not even taken into account in the differential diagnosis, and the frequency of IE detected for the first time during surgery or during a pathoanatomic autopsy reaches 25% [7–8].

Therefore, IE is most often found in patients with congenital heart defects, with prosthetic heart valves, or in the presence of an artificial cardiac pacemaker [9–11]. IE in elderly patients often occurs under the “masks” of other diseases, which complicates the timely diagnosis [11–13]. In this case, the main diagnosis was hidden under several symptoms pathognomonic for other diseases: at first, the “mask” of an acute infectious disease came to the fore, followed by suspicion of cancer, and only in the absence of the effect of treatment and refutation of oncopathology, IE was detected.

The diagnosis of IE can be made in accordance with the modified Duke criteria, according to which the main (large) and auxiliary (small) criteria are distinguished [4–5].

In this clinical case, the authors of this study observed an elderly patient with a combination of a number of diseases, self-treatment of which, as well as prolonged differential diagnosis, led to the late detection of the underlying pathology. The diagnosis was established in connection with the detection of two large diagnostic criteria — the detection of Staphylococcus aureus hemoculture, as well as the visualization of vegetations on the valves during echocardiography. A feature of the observation was the active use of conservative therapy, which was quite successful and allowed moving on to the next stage of treatment.

Taking into account the sensitivity of the pathogen, long-term and massive antibiotic therapy is fundamental in the treatment of IE [4][14]. When verifying in the blood S. aureus in this clinical case, following clinical recommendations, it is necessary to use antibacterial therapy in the following volume: (Flu)cloxacillin or Oxacillin (12 g per day I.V. in 4–6 injections), alternative therapy: Co-trimoxazole (4800 mg/day) and Trimethoprim (960 mg/day I.V. in 4–6 injections) or Clindamycin (1800 mg per day I.V. in 3 injections) [5].

Due to the severity of the course and the late diagnosis of the disease in this case, in addition to conservative therapy, the patient was recommended and underwent surgical treatment — prosthetics of the aortic and mitral valves.

The clinical course of this case proves various variants of IE manifestations, and also confirms the serious need to increasingly suspect the appearance of this pathology in patients who, according to their anamnesis, do not have a predisposition to IE.

Conclusion

Clinical observation indicates the complexity of the IE diagnosis. The disease is characterized by the occurrence of specific manifestations, but at the same time, general symptoms come to the fore more often. It is especially difficult to diagnose cases of IE in elderly people with multiple concomitant pathologies, under the “masks” of which the underlying disease may be hidden.