Infective endocarditis superimposed on a massively calcified severely stenotic congenitally bicuspid aortic valve Syed Sarmast, MD, Jeffrey M. Schussler, MD, Jong M. Ko, BA, and William C. Roberts, MD
We describe a 55-year-old man who presented with a stroke resulting from active infective endocarditis (IE) involving a heavily calcified bicuspid aortic valve. The case highlights the infrequency of IE involving a heavily calcified valve, the inability of the infection to penetrate the calcific deposits, and the ability of the infection to spread to the adjacent soft tissues, leading to ring abscess and its multiple complications.
he aortic valve is the most common site for one or more vegetations to form in infective endocarditis (IE) (1). Since the introduction of corticosteroids and the increased frequency of immunotherapy and intravenous drug addiction, infection involving the aortic valve has most commonly involved a previously structurally normal valve. The next most common aortic valve to be involved by IE was a congenitally malformed bicuspid aortic valve that had functioned normally or had only mild dysfunction (2). IE involving a previously calcified valve is unusual and particularly so when the aortic valve is massively calcified. The present report was prompted by study of a patient who developed IE on a previously heavily calcified, severely stenotic aortic valve.
T
CASE DESCRIPTION A 55-year-old white man, on chronic hemodialysis for endstage renal disease believed to be secondary to diabetes mellitus, was hospitalized because of the sudden onset of confusion. Diabetes mellitus was diagnosed when he was 43 years old (2001), requiring insulin therapy by age 49. Systemic hypertension was diagnosed at age 50. He had a sedentary lifestyle and was obese (body mass index 35 kg/m2). Twelve months earlier, hemodialysis had been initiated; 7 months earlier, a malfunctioning right arm arteriovenous fistula had been repaired; and 1 month earlier, he presented with fever, nausea, vomiting, and abdominal pain. Methicillin-resistant Staphylococcus aureus bacteremia related to a right internal jugular PermaCath infection was diagnosed. During that admission, a grade 2/6 precordial systolic ejection murmur was heard. Echocardiography revealed a calcified stenotic bicuspid aortic valve with trace aortic regurgitation, and a small mobile mass attached to the aortic valve was seen. An aortic root abscess also was seen. He was discharged home to receive intravenous vancomycin for 6 weeks and then returned Proc (Bayl Univ Med Cent) 2014;27(1):37–38
because of confusion. Repeat blood cultures again grew Staphylococcus aureus. He was treated with daptomycin. On July 31, 2010, the aortic valve (bioprosthesis) and proximal portion of the ascending aorta were replaced (the latter was a homograft), the paravalvular abscess was debrided, and the coronary ostial sites were implanted into the homograft. The excised stenotic and infected aortic valve weighed 8.36 g and was congenitally bicuspid (Figure 1). Culture of the excised valve grew methicillin-resistant Staphylococcus aureus. The patient’s early postoperative course was complicated by episodes of paroxysmal atrial fibrillation and nonsustained ventricular tachycardia. One month following the operation, the patient was back at home and continuing his hemodialysis treatments 3 times a week. A successful renal transplant was performed on September 13, 2012, and hemodialysis was discontinued. As of October 2013, he remains active and exercises 30 minutes a day at least 3 times a week. He is currently unemployed and on disability. DISCUSSION The patient described herein with end-stage renal disease requiring chronic hemodialysis had a heavily calcified stenotic congenitally bicuspid aortic valve and developed superimposed IE initiated as a result of infection at the percutaneous dialysis entry site. The infection, unable to grow well in the calcified valve, rapidly spread to the adjoining soft tissue, producing a ring abscess. The unusual feature of the present patient is the development of IE on a massively calcified aortic valve. The normal aortic valve weighs about 0.4 g. Thus, the valve in the present patient (8.36 g) was 20 times heavier than normal, and most of that excessive weight was the result of the calcific deposits, not the superimposed vegetative material. Roberts and Ko (3) initially reported weights of operatively excised stenotic aortic valves in 2003 and from January 1998 to August 2013 had From the Division of Cardiology, Department of Internal Medicine, Baylor University Medical Center at Dallas and the Jack and Jane Hamilton Heart and Vascular Hospital, Dallas, Texas. Corresponding author: Syed Sarmast, MD, Baylor Heart and Vascular Hospital, 621 N. Hall Street, Dallas, TX 75226 (e-mail: [email protected]). 37
weighed 1726 stenotic aortic valves: only 12 (0.7%) weighed >8 g, and none of the other 11 patients had IE. Indeed, the lighter the aortic valve, the greater the likelihood of its being complicated by IE (2). IE involving a stenotic aortic valve is far less common than IE involving a nonstenotic aortic valve. Fernicola and Roberts (4) studied at necropsy 96 patients with active IE involving the aortic valve: 25 (26%) had underlying stenosis and 71 (74%) had an underlying nonstenotic valve. Of the 25 with underlying stenosis, 21 (84%) had a ring abscess and 10 (40%) had an underlying congenitally bicuspid valve; of the 71 with a nonstenotic aortic valve, 37 (52%) had a ring abscess (P = 0.005) and 21 (30%), a congenitally bicuspid valve (ns). The patient described had two reasons for having a heavily calcified aortic valve: 1) the underlying bicuspid condition (2), and 2) the presence of end-stage renal disease with chronic hemodialysis (5).
a
b
1.
2.
3.
4.
5.
Figure 1. (a) Photograph of the operatively excised stenotic aortic valve and (b) radiograph of the valve in the patient described.
38
Arnett EN, Roberts WC. Pathology of active infective endocarditis: a necropsy analysis of 192 patients. Thorac Cardiovasc Surg 1982;30(6):327– 335. Roberts WC, Vowels TJ, Ko JM. Natural history of adults with congenitally malformed aortic valves (unicuspid or bicuspid). Medicine (Baltimore) 2012;91(6):287–308. Roberts WC, Ko JM. Weights of operatively-excised stenotic unicuspid, bicuspid, and tricuspid aortic valves and their relation to age, sex, body mass index, and presence or absence of concomitant coronary artery bypass grafting. Am J Cardiol 2003;92(9):1057–1065. Roberts WC, Oluwole BO, Fernicola DJ. Comparison of active infective endocarditis involving a previously stenotic versus a previously nonstenotic aortic valve. Am J Cardiol 1993;71(12):1082–1088. Roberts WC, Taylor MA, Shirani J. Cardiac findings at necropsy in patients with chronic kidney disease maintained on chronic hemodialysis. Medicine (Baltimore) 2012;91(3):165–178.
Baylor University Medical Center Proceedings
Volume 27, Number 1
We describe a 55-year-old man who presented with a stroke resulting from active infective endocarditis (IE) involving a heavily calcified bicuspid aortic valve. The case highlights the infrequency of IE involving a heavily calcified valve, the inability of the infection to penetrate the calcific deposits, and the ability of the infection to spread to the adjacent soft tissues, leading to ring abscess and its multiple complications.
he aortic valve is the most common site for one or more vegetations to form in infective endocarditis (IE) (1). Since the introduction of corticosteroids and the increased frequency of immunotherapy and intravenous drug addiction, infection involving the aortic valve has most commonly involved a previously structurally normal valve. The next most common aortic valve to be involved by IE was a congenitally malformed bicuspid aortic valve that had functioned normally or had only mild dysfunction (2). IE involving a previously calcified valve is unusual and particularly so when the aortic valve is massively calcified. The present report was prompted by study of a patient who developed IE on a previously heavily calcified, severely stenotic aortic valve.
T
CASE DESCRIPTION A 55-year-old white man, on chronic hemodialysis for endstage renal disease believed to be secondary to diabetes mellitus, was hospitalized because of the sudden onset of confusion. Diabetes mellitus was diagnosed when he was 43 years old (2001), requiring insulin therapy by age 49. Systemic hypertension was diagnosed at age 50. He had a sedentary lifestyle and was obese (body mass index 35 kg/m2). Twelve months earlier, hemodialysis had been initiated; 7 months earlier, a malfunctioning right arm arteriovenous fistula had been repaired; and 1 month earlier, he presented with fever, nausea, vomiting, and abdominal pain. Methicillin-resistant Staphylococcus aureus bacteremia related to a right internal jugular PermaCath infection was diagnosed. During that admission, a grade 2/6 precordial systolic ejection murmur was heard. Echocardiography revealed a calcified stenotic bicuspid aortic valve with trace aortic regurgitation, and a small mobile mass attached to the aortic valve was seen. An aortic root abscess also was seen. He was discharged home to receive intravenous vancomycin for 6 weeks and then returned Proc (Bayl Univ Med Cent) 2014;27(1):37–38
because of confusion. Repeat blood cultures again grew Staphylococcus aureus. He was treated with daptomycin. On July 31, 2010, the aortic valve (bioprosthesis) and proximal portion of the ascending aorta were replaced (the latter was a homograft), the paravalvular abscess was debrided, and the coronary ostial sites were implanted into the homograft. The excised stenotic and infected aortic valve weighed 8.36 g and was congenitally bicuspid (Figure 1). Culture of the excised valve grew methicillin-resistant Staphylococcus aureus. The patient’s early postoperative course was complicated by episodes of paroxysmal atrial fibrillation and nonsustained ventricular tachycardia. One month following the operation, the patient was back at home and continuing his hemodialysis treatments 3 times a week. A successful renal transplant was performed on September 13, 2012, and hemodialysis was discontinued. As of October 2013, he remains active and exercises 30 minutes a day at least 3 times a week. He is currently unemployed and on disability. DISCUSSION The patient described herein with end-stage renal disease requiring chronic hemodialysis had a heavily calcified stenotic congenitally bicuspid aortic valve and developed superimposed IE initiated as a result of infection at the percutaneous dialysis entry site. The infection, unable to grow well in the calcified valve, rapidly spread to the adjoining soft tissue, producing a ring abscess. The unusual feature of the present patient is the development of IE on a massively calcified aortic valve. The normal aortic valve weighs about 0.4 g. Thus, the valve in the present patient (8.36 g) was 20 times heavier than normal, and most of that excessive weight was the result of the calcific deposits, not the superimposed vegetative material. Roberts and Ko (3) initially reported weights of operatively excised stenotic aortic valves in 2003 and from January 1998 to August 2013 had From the Division of Cardiology, Department of Internal Medicine, Baylor University Medical Center at Dallas and the Jack and Jane Hamilton Heart and Vascular Hospital, Dallas, Texas. Corresponding author: Syed Sarmast, MD, Baylor Heart and Vascular Hospital, 621 N. Hall Street, Dallas, TX 75226 (e-mail: [email protected]). 37
weighed 1726 stenotic aortic valves: only 12 (0.7%) weighed >8 g, and none of the other 11 patients had IE. Indeed, the lighter the aortic valve, the greater the likelihood of its being complicated by IE (2). IE involving a stenotic aortic valve is far less common than IE involving a nonstenotic aortic valve. Fernicola and Roberts (4) studied at necropsy 96 patients with active IE involving the aortic valve: 25 (26%) had underlying stenosis and 71 (74%) had an underlying nonstenotic valve. Of the 25 with underlying stenosis, 21 (84%) had a ring abscess and 10 (40%) had an underlying congenitally bicuspid valve; of the 71 with a nonstenotic aortic valve, 37 (52%) had a ring abscess (P = 0.005) and 21 (30%), a congenitally bicuspid valve (ns). The patient described had two reasons for having a heavily calcified aortic valve: 1) the underlying bicuspid condition (2), and 2) the presence of end-stage renal disease with chronic hemodialysis (5).
a
b
1.
2.
3.
4.
5.
Figure 1. (a) Photograph of the operatively excised stenotic aortic valve and (b) radiograph of the valve in the patient described.
38
Arnett EN, Roberts WC. Pathology of active infective endocarditis: a necropsy analysis of 192 patients. Thorac Cardiovasc Surg 1982;30(6):327– 335. Roberts WC, Vowels TJ, Ko JM. Natural history of adults with congenitally malformed aortic valves (unicuspid or bicuspid). Medicine (Baltimore) 2012;91(6):287–308. Roberts WC, Ko JM. Weights of operatively-excised stenotic unicuspid, bicuspid, and tricuspid aortic valves and their relation to age, sex, body mass index, and presence or absence of concomitant coronary artery bypass grafting. Am J Cardiol 2003;92(9):1057–1065. Roberts WC, Oluwole BO, Fernicola DJ. Comparison of active infective endocarditis involving a previously stenotic versus a previously nonstenotic aortic valve. Am J Cardiol 1993;71(12):1082–1088. Roberts WC, Taylor MA, Shirani J. Cardiac findings at necropsy in patients with chronic kidney disease maintained on chronic hemodialysis. Medicine (Baltimore) 2012;91(3):165–178.
Baylor University Medical Center Proceedings
Volume 27, Number 1
