|INTERESTING CASE REPORT
|Year : 2022 | Volume
| Issue : 1 | Page : 72-75
Mega Coronary Arteries with Obstructive Coronary Artery Disease in Hypertrophic Obstructive Cardiomyopathy: A Case Report and Literature Review
Debasish Das, Debasis Acharya, Tutan Das, Subhas Pramanik
Department of Cardiology, All India Institute of Medical Sciences, Bhubaneswar, Odisha, India
|Date of Submission||29-Jul-2021|
|Date of Acceptance||02-Oct-2021|
|Date of Web Publication||01-Feb-2022|
Dr. Debasish Das
Department of Cardiology, All India Institute of Medical Sciences, Bhubaneswar - 751 019, Odisha
Source of Support: None, Conflict of Interest: None
We report a rare case of hypertrophic obstructive cardiomyopathy (HOCM) presenting with mega coronary arteries with obstructive coronary artery disease. Interestingly, the patient had large septals, large diagonals, large obtuse marginal with a large left atrial branch, and a large conus almost mimicking a duplicate right coronary artery. Because of massive left ventricular hypertrophy, to overcome the supply-demand mismatch, coronary arteries may become large or with more arborization in hypertrophic cardiomyopathy but the same is rarely encountered in routine clinical practice. Our case is a rare illustration of the simultaneous presence of mega coronary arteries and critical obstructive coronary artery disease in HOCM in a young male of 38 years of age.
Keywords: Cardiomyopathy, hypertrophic, mega coronaries, obstructive
|How to cite this article:|
Das D, Acharya D, Das T, Pramanik S. Mega Coronary Arteries with Obstructive Coronary Artery Disease in Hypertrophic Obstructive Cardiomyopathy: A Case Report and Literature Review. J Indian Acad Echocardiogr Cardiovasc Imaging 2022;6:72-5
|How to cite this URL:|
Das D, Acharya D, Das T, Pramanik S. Mega Coronary Arteries with Obstructive Coronary Artery Disease in Hypertrophic Obstructive Cardiomyopathy: A Case Report and Literature Review. J Indian Acad Echocardiogr Cardiovasc Imaging [serial online] 2022 [cited 2022 May 23];6:72-5. Available from: https://www.jiaecho.org/text.asp?2022/6/1/72/337107
| Introduction|| |
Hypertrophic cardiomyopathy (HCM) is a genetic cardiovascular disease characterized by an increase in left ventricular (LV) wall thickness which cannot be explained by abnormal loading conditions. Patients with HCM often suffer from exertional dyspnea, which may partly be due to supply-demand mismatch of coronary blood flow to hypertrophied muscles., It is hypothesized that to overcome the supply-demand mismatch, the coronary arteries may become larger in size but the same is infrequently encountered in routine clinical practice. Our case is a rare description of the simultaneous presence of mega coronary arteries and obstructive coronary artery disease (CAD), without the presence of conventional risk factors, in a young gentleman with HCM.
| Case Report|| |
A 38-year-old young male without major conventional cardiovascular risk factors presented to the cardiology outpatient department with the chief complaint of rest angina for the past 2 days, with New York Heart Association class III shortness of breath. At presentation, his blood pressure was 116/80 mmHg in the right arm supine position with a pulse rate of 82 beats/min. His previous electrocardiogram (ECG) revealed the presence of significant LV hypertrophy with strain [Figure 1]. However, ECG at this presentation revealed the features of evolved anterior wall ST-elevation myocardial infarction (STEMI) with loss of LV force in lateral precordial leads [Figure 2]. The high-sensitive troponin was markedly elevated (2654 ng/ml). Echocardiography revealed the presence of asymmetrical septal hypertrophy with an interventricular septal thickness of 24 mm with a posterior wall thickness of 12 mm with septum to posterior wall ratio of 2 (>1.3) [Figure 3]. M-mode echocardiography revealed a grade III systolic anterior motion (SAM) of mitral leaflet (AML) [Figure 4]. Grading of SAM of AML is done as follows:
|Figure 1: Electrocardiogram at presentation with anterior wall ST-elevation myocardial infarction with loss of left ventricular force (V5, V6)|
Click here to view
|Figure 2: The patient's previous electrocardiogram showing left ventricular hypertrophy with systolic strain|
Click here to view
|Figure 4: M-mode echocardiography showing grade III systolic anterior motion of the anterior mitral leaflet|
Click here to view
- Grade 1 - AML buckling toward LVOT 10 mm away from the septum
- Grade 2 - AML buckling toward LVOT within 10 mm from the septum
- Grade 3 - AML buckling and touching septum but for <30% of systole
- Grade 4 - AML buckling and touching septum for more than 30% of systole.
Color Doppler revealed turbulence across the LVOT [Figure 5] with a provocative gradient of 110 mmHg [Figure 6].
Echocardiographic distribution of hypertrophy involving the septum and anterolateral free wall was suggestive of Maron's type III phenotype of HCM. There was mild hypokinesia of the LV anterior wall with borderline LV systolic function (ejection fraction – 55%) and grade I diastolic dysfunction. His reverse transcriptase-polymerase chain reaction for coronavirus disease 2019 was negative, and biochemical investigations were within normal limit.
In view of ECG evidence of anterior wall myocardial infarction with loss of LV force, high troponin positivity, and ongoing angina, he was subjected to right transradial coronary angiogram which revealed a critical obstruction in the mid-left anterior descending coronary artery (LAD) at LAD-diagonal bifurcation [Figure 7]. Interestingly, the patient had mega coronary arteries (LAD – 4.2 mm, left circumflex – 4.6 mm, right coronary artery [RCA] – 5.2 mm) with large septals (>2 mm), large diagonal branches (>3 mm), large obtuse marginal (3.7 mm), large left atrial branch from left circumflex coronary artery (2.8 mm), and a large conus branch almost mimicking duplicate RCA (2.6 mm) [Figure 7], [Figure 8], [Figure 9]. The presence of large or mega coronary arteries with good myocardial perfusion may be the contributing factor toward the preservation of LV systolic function in spite of an acute anterior wall STEMI with critical mid LAD-diagonal bifurcation lesion in this patient with hypertrophic obstructive cardiomyopathy (HOCM). We revascularized the critical lesion with a drug-eluting stent of 2.75 mm × 36 mm size and achieved Thrombolysis In Myocardial Infarction III flow. We managed the patient with dual antiplatelets with aspirin, ticagrelor, and high-dose statin, along with beta-blocker metoprolol 50 mg twice daily and ranolazine 500 mg twice daily to homogenize the electrical dispersion across myofiber disarray in HOCM. He was discharged uneventfully the next day morning. Our case is a rare illustration of the simultaneous presence of large or mega coronary arteries and critically obstructive CAD in a case of HOCM.
|Figure 7: Mega obtuse marginal and a large left atrial branch in right anterior oblique 30-degrees caudal view|
Click here to view
|Figure 8: Mega septals and mega diagonals in anteroposterior cranial view|
Click here to view
|Figure 9: Mega conus branch from right coronary artery in the anteroposterior cranial view|
Click here to view
| Discussion|| |
HCM is a genetic cardiovascular disease. It is characterized by an increase in LV wall thickness which cannot be explained by abnormal loading conditions. This disorder is caused by a mutation in cardiac sarcomere protein genes and is most frequently transmitted as an autosomal dominant trait. HCM has a variable presentation, resulting from a constellation of pathological abnormalities that characterize it. Myocardial ischemia is one of the manifestations of HCM. However, most of the patients with HCM have normal or nonobstructive coronary arteries, and hence, myocardial ischemia is mostly secondary to supply-demand mismatch due to massive myocardial hypertrophy. It is hypothesized that to meet the supply-demand mismatch, the coronary arteries may sometimes become large in caliber. Yet, it is rare to encounter such large or mega coronary arteries in HCM. The presence of obstructive disease in such large arteries at a young age and in the absence of major conventional cardiovascular risk factors is even rarer. Our case is thus a rare illustration of the existence of two contradictory findings, i.e. mega coronary arteries in one aspect and the presence of obstructive CAD in another aspect, simultaneously in a young patient with HOCM. To the best of our knowledge, such a combination of abnormalities has not been described in the literature so far.
Maron has described that abnormal small intramural coronary arteries constitute a common morphological component in HOCM. These small arteries often appear in the interventricular septum rather than the LV free wall and bear no relation to the site of muscular hypertrophy or dynamic obstruction. These vessels are typically 100–400 μm in diameter (average 300 μm) and appear narrowed due to hypertrophy of the intima and media due to proliferation of smooth muscle, collagen, elastic fibers, and mucoid deposits. Clusters of abnormal intramural arteries are present at the border of patchy fibrosis in HCM. It was hypothesized that neovascularization secondary to replacement fibrosis might be the cause behind the clustering of these small vessels around fibrosis in HCM. These small intramural arteries do not have the predilection for subepicardial or subendocardial location.
Myocardial ischemia in HCM may result from several mechanisms. Sayin et al. illustrated angiographic systolic compression of intramural coronary arteries as the cause of angina in a 43-year-old patient with HCM. Waterson et al. described the presence of coronary fistula from the left main coronary artery and LAD to the pulmonary artery as the cause of coronary ischemia in a case of a 63-year-old male with HCM. The coronary arteries were not ectatic or aneurysmal. Basso et al. described myocardial bridging as a frequent component in patients with HCM but it is not associated with an increased risk of sudden cardiac death. Thus, most of the literature in HCM describes narrowing of the coronary arteries in the form of systolic narrowing, myocardial bridging, or predominance of intramural constricted small arteries. Obstructive CAD is believed to be a less common cause of myocardial ischemia in HCM.
Cokkinos et al. described that the incidence of CAD was higher in HCM patients above 45 years of age. Thavapalachandran et al. described a case of significant CAD involving LAD and left circumflex coronary artery in the presence of apical HCM. Harjai et al. reported that obstructive CAD could be present in up to 25% patients with HCM after the age of 45.
The American Heart Association guideline states that invasive coronary angiography is indicated in HCM patients with chest pain with a high likelihood of CAD, whereas noninvasive imaging is indicated in HCM patients with chest pain with a low likelihood of CAD. In our patient, ECG was consistent with evolved anterior wall myocardial infarction, which prompted us to perform invasive coronary angiography.
Gupta et al. described that HCM patients with acute STEMI had a lower risk-adjusted in-hospital mortality. This could be due to the presence of good muscle mass and relative preservation of LV systolic function. In our patient too, LV systolic function was relatively preserved, possibly due to the presence of multiple large or mega coronary arteries with significant underlying LV hypertrophy. The patient was discharged uneventfully from the hospital. Any intervention for relieving LVOT obstruction was not contemplated during the present admission because he had just suffered a myocardial infraction. Moreover, it would be difficult to predict how healing and fibrosis of the infarcted septum and LV anterior wall would influence LVOT obstruction during the follow-up.
| Conclusion|| |
Although the presence of microvascular dysfunction in HCM is well reported, our case is a rare description of the presence of large or mega coronary arteries in a patient with HOCM with critical obstructive CAD. Our case is thus a rare illustration of the simultaneous presence of two contradictory pathophysiologies, i.e. presence of large or mega coronary arteries and critically obstructive CAD in a young patient with HOCM.
Declaration of patient consent
The authors certify that they have obtained all appropriate patient consent forms. In the form the patient (s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initial s will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
| References|| |
Harjai KJ, Cheirif J, Murgo JP. Ischemia and atherosclerotic coronary artery disease in patients with hypertrophic cardiomyopathy: A review of incidence, pathophysiological mechanisms, clinical implications and management strategies. Coron Artery Dis 1996;7:183-7.
Stroumpoulis KI, Pantazopoulos IN, Xanthos TT. Hypertrophic cardiomyopathy and sudden cardiac death. World J Cardiol 2010;2:289-98.
Marszalek RJ, John Solaro R, Wolska BM. Coronary arterial vasculature in the pathophysiology of hypertrophic cardiomyopathy. Pflugers Arch 2019;471:769-80.
Reant P, Donal E, Schnell F, Reynaud A, Daudin M, Pillois X, et al
. Clinical and imaging description of the Maron subtypes of hypertrophic cardiomyopathy. Int J Cardiovasc Imaging 2015;31:47-55.
Cokkinos DV, Krajcer Z, Leachman RD. Hypertrophic cardiomyopathy and associated coronary artery disease. Texas Heart Inst J 1985;12:147-51.
Maron BJ. Hypertrophic cardiomyopathy and coronary arteries. Pan Vascular Med 2002;61:980-81.
Sayin MR, Dogan SM, Karabag T, Akpinar I, Aydin M. Systolic compression of intramural coronary arteries in hypertrophic cardiomyopathy. Case Rep Cardiol 2012;12:1-3.
Waterson DF, Murphy TM, Creery CM, Hanlol RO. Hypertrophic cardiomyopathy and coronary fistulae. Br J Cardiol 2017; 24:118-9.
Basso C, Thiene G, Mackey-Bojack S, Frigo AC, Corrado D, Maron BJ. Myocardial bridging, a frequent component of the hypertrophic cardiomyopathy phenotype, lacks systematic association with sudden cardiac death. Eur Heart J 2009;30:1627-34.
Thavapalachandran S, Wong D, Mardini M, Tang T. Apical hypertrophic cardiomyopathy with coronary artery disease. Heart Lung Circ 2015;24:492.
Ommen SR, Mital S, Burke MA, Day SM, Deswal A, Elliott P, et al
. 2020 AHA/ACC guideline for the diagnosis and treatment of patients with hypertrophic cardiomyopathy: A report of the American college of cardiology/American heart association joint committee on clinical practice guidelines. Circulation 2020;142:e558-631.
Gupta T, Harikrishnan P, Kolte D, Khera S, Aronow WS, Mujib M, et al
. Outcomes of acute myocardial infarction in patients with hypertrophic cardiomyopathy. Am J Med 2015;128:879-87.e1.
[Figure 1], [Figure 2], [Figure 3], [Figure 4], [Figure 5], [Figure 6], [Figure 7], [Figure 8], [Figure 9]