Julian
Well-known member
By no means is this a license for anyone to stop their ACT but it's an amazing observation. :eek2:
I'm not sure if this has been posted before but I found it about a year ago and thought I would share it. Below is the link and below the link is the copy and pasted text from the link.
http://icvts.ctsnetjournals.org/cgi/content/full/8/2/263
Case report - Valves
Mechanical aortic valve without anticoagulation for twenty-three years
Shikha Sharma, Kirk McMurty, Narisety Chalapathy and Abdul Ameen*
Department of Cardiology, Jersey City Medical Center, 355 Grand Street, Jersey City, NJ 07302, USA
Received 28 July 2008; received in revised form 24 October 2008; accepted 29 October 2008
*Corresponding author. Tel.: +1-551-697-0242; fax: +1-800-203-4024.
E-mail address: [email protected] (A. Ameen).
Current guidelines necessitate varying degrees of long-term anticoagulation in patients with mechanical heart valve(s) to prevent thrombotic and embolic complications. We describe a patient with a functioning aortic mechanical valve without anticoagulation for 23 years. A 68-year-old man had an aortic valve (St Jude Medical) replacement in 1984. His native valve was incompetent from infective endocarditis. He discontinued Coumadin three months after the surgery. He presented 23 years later with palpitations for one month. Further work-up revealed a NYHA class I function, normal sinus rhythm, normal sized heart on chest X-ray, normal systolic and diastolic function on echocardiography. Mean transaortic gradient was 19 mmHg and calculated valve area was 1.48 cm2. Fluoroscopy showed normal excursions of the mechanical aortic valve. Exercise stress test did not show any limitation in effort tolerance or perfusion defects. He was discharged on daily aspirin and clopidogrel.
Key Words: Mechanical valve; Anticoagulation; Aortic valve; Thrombosis; Embolism; Bleeding
Mechanical valves composed of metal or carbon alloys have the advantage of long-term durability, but they carry an increased risk of thrombo-embolism as well as definite risk of bleeding secondary to anticoagulation [1]. We describe a case of functioning mechanical aortic valve (St Jude Medical) without anticoagulant therapy for twenty-three years.
A 68-year-old African-American man with a history of systemic hypertension was hospitalized with frequent episodes of palpitation at rest for one month duration. He underwent aortic valve (St Jude Medical) replacement 23 years previously for infective endocarditis secondary to intravenous drug abuse. He discontinued coumadin following an ‘allergic’ reaction three months after surgery. He had no medical follow-up.
He was New York Heart Association functional class-1. Vital signs included a regular heart rate of 80 beats per minute and blood pressure of 150/90. Cardiac auscultation revealed a normal intensity first heart sound and loud mechanical component of aortic second heart sound and grade 3/6 systolic murmur at the aortic area. The rest of the physical examination was unremarkable.
His hemoglobin was 150 g/l and platelet count was 275x109/l. Troponin of 0.02 µg/l and B-type natriuretic peptide of 42 ng/l were in normal range. Liver, kidney and thyroid function tests were within normal limits. His international normalized ratio (INR) was 1.2. Electrocardiography demonstrated normal sinus rhythm. Twenty-four hour Holter monitor did not reveal any evidence of arrhythmia. Chest X-ray showed a normal sized heart.
Trasthoracic echocardiogram (TTE) showed normal left ventricular systolic and diastolic function. Prosthetic aortic valve was noted but reverberation artifact precluded valvular morphological assessment. Peak velocity across the aortic valve was 3.07 m/s, mean transaortic gradient was 19 mmHg and calculated aortic valve area was 1.48 cm2. Pulmonary pressures were normal. Transesophageal echocardiogram revealed a bileaflet aortic mechanical prosthesis with normal excursions. There was no evidence of thrombus, pannus formation or regurgitation. Fluoroscopy showed normal movement of the mechanical aortic valve. Exercise stress test did not reveal any significant symptoms or hemodynamic abnormalities or EKG changes or perfusion defects, with excellent exercise capacity. The patient remained asymptomatic during the hospital course. He did not complain of shortness of breath. He was discharged on aspirin and clopidogrel as he refused to be placed on coumadin.
Prosthetic valve thrombosis and subsequent systemic embolization are well-known complications of mechanical valves, which mandate the patient to receive long-term anticoagulant therapy [1]. However, most results of antithrombotic prophylaxis are from non-randomized case series without controls [2]. Uncomplicated functioning without anticoagulation of various mechanical valves including Bjork–Shiley (B-S), Star–Edwards (S-E) and Lillehei–Kaster (L-K) in aortic or mitral positions have been reported (Table 1) [3–8]. It is observed that mechanical valves at aortic position are durable without anticoagulation irrespective of type of valve used as Bjork–Shiley, Starr–Edwards or St Jude Medical as in our case [2–7]. Interestingly, Andersen and Alstrup followed 43 patients (mean age 52 years) who discontinued anticoagulation after 12 months of isolated mechanical aortic valve replacement and were followed for a mean period of 7.2 years without anticoagulation [3]. They noted after 10 years, 41% incidence of thromoboembolic events and 17% mortality.
Table 1 Reported cases of well functioning mechanical valve without anticoagulation
Bjork et al. postulated that all thromboembolic complications in mechanical heart valves start from a thrombus lining that covers the suture ring [9, 10]. The thrombus organizes to a fibrous white sheet over the suture ring, which then can protrude out over the polished surface of the valve ring flange. Pieces of the thrombus can be knocked off by the disc and cause emboli. To diminish thrombo-embolic complications, one must either prevent this thrombus from protruding into the groove between the suture ring and the valve flange or allow the thrombus to be organized as a thin covering with endothelium-like cells as a continuation from the suture ring over the valve flange. This type of covering was obtained during a short period of anticoagulation by applying a microporous surface to the Björk–Shiley Monostrut mitral valve. They observed two goats with microporous surfaced B-S mitral valve without anticoagulation for five years. These animals had a total of six pregnancies with delivery of 14 newborns without any thrombotic complications [9, 10]. The same group in 1999 demonstrated the favorable outcome in 12 patients with Bjork–Shiley Monstrut mechanical mitral valve with a microporous surface without anticoagulation for 11–13 years [4].
It is unusual that a functioning St Jude Medical aortic valve is present without anticoagulation for over twenty-three years. The potential factors underlying in the normal valvular mechanics in our patient remains unclear. Guidelines are sorely needed in patients with mechanical valves who subsequently develop a contraindication and that this case, like many others, at the least gives some direction in patients with mechanical valves in the aortic position.
I'm not sure if this has been posted before but I found it about a year ago and thought I would share it. Below is the link and below the link is the copy and pasted text from the link.
http://icvts.ctsnetjournals.org/cgi/content/full/8/2/263
Case report - Valves
Mechanical aortic valve without anticoagulation for twenty-three years
Shikha Sharma, Kirk McMurty, Narisety Chalapathy and Abdul Ameen*
Department of Cardiology, Jersey City Medical Center, 355 Grand Street, Jersey City, NJ 07302, USA
Received 28 July 2008; received in revised form 24 October 2008; accepted 29 October 2008
*Corresponding author. Tel.: +1-551-697-0242; fax: +1-800-203-4024.
E-mail address: [email protected] (A. Ameen).
Current guidelines necessitate varying degrees of long-term anticoagulation in patients with mechanical heart valve(s) to prevent thrombotic and embolic complications. We describe a patient with a functioning aortic mechanical valve without anticoagulation for 23 years. A 68-year-old man had an aortic valve (St Jude Medical) replacement in 1984. His native valve was incompetent from infective endocarditis. He discontinued Coumadin three months after the surgery. He presented 23 years later with palpitations for one month. Further work-up revealed a NYHA class I function, normal sinus rhythm, normal sized heart on chest X-ray, normal systolic and diastolic function on echocardiography. Mean transaortic gradient was 19 mmHg and calculated valve area was 1.48 cm2. Fluoroscopy showed normal excursions of the mechanical aortic valve. Exercise stress test did not show any limitation in effort tolerance or perfusion defects. He was discharged on daily aspirin and clopidogrel.
Key Words: Mechanical valve; Anticoagulation; Aortic valve; Thrombosis; Embolism; Bleeding
Mechanical valves composed of metal or carbon alloys have the advantage of long-term durability, but they carry an increased risk of thrombo-embolism as well as definite risk of bleeding secondary to anticoagulation [1]. We describe a case of functioning mechanical aortic valve (St Jude Medical) without anticoagulant therapy for twenty-three years.
A 68-year-old African-American man with a history of systemic hypertension was hospitalized with frequent episodes of palpitation at rest for one month duration. He underwent aortic valve (St Jude Medical) replacement 23 years previously for infective endocarditis secondary to intravenous drug abuse. He discontinued coumadin following an ‘allergic’ reaction three months after surgery. He had no medical follow-up.
He was New York Heart Association functional class-1. Vital signs included a regular heart rate of 80 beats per minute and blood pressure of 150/90. Cardiac auscultation revealed a normal intensity first heart sound and loud mechanical component of aortic second heart sound and grade 3/6 systolic murmur at the aortic area. The rest of the physical examination was unremarkable.
His hemoglobin was 150 g/l and platelet count was 275x109/l. Troponin of 0.02 µg/l and B-type natriuretic peptide of 42 ng/l were in normal range. Liver, kidney and thyroid function tests were within normal limits. His international normalized ratio (INR) was 1.2. Electrocardiography demonstrated normal sinus rhythm. Twenty-four hour Holter monitor did not reveal any evidence of arrhythmia. Chest X-ray showed a normal sized heart.
Trasthoracic echocardiogram (TTE) showed normal left ventricular systolic and diastolic function. Prosthetic aortic valve was noted but reverberation artifact precluded valvular morphological assessment. Peak velocity across the aortic valve was 3.07 m/s, mean transaortic gradient was 19 mmHg and calculated aortic valve area was 1.48 cm2. Pulmonary pressures were normal. Transesophageal echocardiogram revealed a bileaflet aortic mechanical prosthesis with normal excursions. There was no evidence of thrombus, pannus formation or regurgitation. Fluoroscopy showed normal movement of the mechanical aortic valve. Exercise stress test did not reveal any significant symptoms or hemodynamic abnormalities or EKG changes or perfusion defects, with excellent exercise capacity. The patient remained asymptomatic during the hospital course. He did not complain of shortness of breath. He was discharged on aspirin and clopidogrel as he refused to be placed on coumadin.
Prosthetic valve thrombosis and subsequent systemic embolization are well-known complications of mechanical valves, which mandate the patient to receive long-term anticoagulant therapy [1]. However, most results of antithrombotic prophylaxis are from non-randomized case series without controls [2]. Uncomplicated functioning without anticoagulation of various mechanical valves including Bjork–Shiley (B-S), Star–Edwards (S-E) and Lillehei–Kaster (L-K) in aortic or mitral positions have been reported (Table 1) [3–8]. It is observed that mechanical valves at aortic position are durable without anticoagulation irrespective of type of valve used as Bjork–Shiley, Starr–Edwards or St Jude Medical as in our case [2–7]. Interestingly, Andersen and Alstrup followed 43 patients (mean age 52 years) who discontinued anticoagulation after 12 months of isolated mechanical aortic valve replacement and were followed for a mean period of 7.2 years without anticoagulation [3]. They noted after 10 years, 41% incidence of thromoboembolic events and 17% mortality.
Table 1 Reported cases of well functioning mechanical valve without anticoagulation
Bjork et al. postulated that all thromboembolic complications in mechanical heart valves start from a thrombus lining that covers the suture ring [9, 10]. The thrombus organizes to a fibrous white sheet over the suture ring, which then can protrude out over the polished surface of the valve ring flange. Pieces of the thrombus can be knocked off by the disc and cause emboli. To diminish thrombo-embolic complications, one must either prevent this thrombus from protruding into the groove between the suture ring and the valve flange or allow the thrombus to be organized as a thin covering with endothelium-like cells as a continuation from the suture ring over the valve flange. This type of covering was obtained during a short period of anticoagulation by applying a microporous surface to the Björk–Shiley Monostrut mitral valve. They observed two goats with microporous surfaced B-S mitral valve without anticoagulation for five years. These animals had a total of six pregnancies with delivery of 14 newborns without any thrombotic complications [9, 10]. The same group in 1999 demonstrated the favorable outcome in 12 patients with Bjork–Shiley Monstrut mechanical mitral valve with a microporous surface without anticoagulation for 11–13 years [4].
It is unusual that a functioning St Jude Medical aortic valve is present without anticoagulation for over twenty-three years. The potential factors underlying in the normal valvular mechanics in our patient remains unclear. Guidelines are sorely needed in patients with mechanical valves who subsequently develop a contraindication and that this case, like many others, at the least gives some direction in patients with mechanical valves in the aortic position.
