Prompt Recognition and Percutaneous Coronary Intervention Leads to Favorable Myocardial Recovery After ST-Segment Elevation Myocardial Infarction Secondary to Acute Promyelocytic Leukemia: Pediatric Case Report

45

C A S E R E P O R T

Prompt Recognition and Percutaneous Coronary Intervention Leads to Favorable Myocardial Recovery After ST-Segment Elevation Myocardial Infarction Secondary to Acute Promyelocytic Leukemia: Pediatric Case Report

Tamara O. Thomas • Preeti Ramachandran •

John L. Jefferies • Robert H. Beekman •

Kan Hor • Angela Lorts

Abstract

Acute myocardial infarction (AMI) is extre-mely rare in children, and unlike the adult disease, the etiology of the infarction is rarely due to atherosclerotic coronary disease. This unique reported case involved a 15-year-old boy with severe chest pain who presented with an ST-segment-elevation myocardial infarction secondary to in situ thrombus formation in the left anterior descending (LAD) coronary artery. The initial electrocardiogram (ECG) had a Q-wave pattern in V6 and ST depression in the inferior leads with ST-segment elevation in reciprocal leads. The cardiac enzymes and routine labs showed evi-dence of myocardial damage. The boy was urgently taken to the cardiac catheterization laboratory for percutaneous coronary intervention, where complete occlusion of the LAD was found and successfully stented. Eventually, a peripheral blood smear showed pancytopenia with 38 % hypergranular blast-like cells consistent with acute myeloid leukemia (AML), and chemotherapy with all-transretinoic acid was implemented. This first pediatric case report of an AML-associated AMI emphasizes the benefit resulting from expedient reperfusion of the ischemic myocardium by quick reestablishment of coronary perfusion. It also emphasizes the limitations of existing noninvasive tech-nologies in detecting myocardial viability.

T. O. Thomas (&) P. Ramachandran J. L. Jefferies R. H. Beekman K. Hor A. Lorts

The Heart Institute, Cincinnati Children’s Hospital Medical Center, 3333 Burnet Avenue-ML 2003, Cincinnati, OH 45229, USA

e-mail: tamara.thomas@cchmc.org

A. Lorts

e-mail: angela.lorts@cchmc.org

Keywords

Acute myocardial infarction Acute promyelocytic leukemia ST-segment-elevation myocardial infarction Pediatric Percutaneous coronary intervention

Acute myocardial infarction (AMI) is extremely rare in children. Unlike the adult disease, the etiology of the infarction rarely is due to atherosclerotic coronary disease but is more commonly the manifestation of a systemic illness. The rarity and diverse etiologies of pediatric myocardial infarctions necessitate case by case manage-ment decisions and an outcome that often is difficult to predict. There is not adequate literature to determine whether the adult data on intervention, post-intervention imaging, and myocardial recovery is applicable to children.

This unique reported case of a child who presented with an ST-segment-elevation myocardial infarction (STEMI) secondary to in situ thrombus formation in the left anterior descending (LAD) coronary artery emphasizes the impor-tance of prompt diagnosis and intervention for quick reestablishment of coronary perfusion and illustrates the limitations of existing noninvasive technologies in detect-ing myocardial viability.

Case Report

A 15-year-old previously healthy boy presented to the emergency room with extreme anxiety, nausea, vomiting, and severe chest pain rated 9 on a pain scale of 1–10. He reported that 1 month before presentation he experienced an increase in bruising, intermittent bleeding after brushing his teeth, and a decrease in exercise tolerance.

The initial medical evaluation yielded a STEMI on an electrocardiogram (ECG) with a Q-wave pattern in V6 and ST depression in inferior leads with ST segment elevation in reciprocal leads (Fig. 1a, b). Cardiac enzymes and routine labs were obtained, which showed evidence of myocardial damage and derangements in the hematologic system (Table 1). An initial echocardiogram demonstrated low normal left ventric-ular (LV) systolic performance with mild mitral regurgitation.

The boy was urgently taken to the cardiac catheteriza-tion laboratory due to concerns of compromised coronary perfusion with resulting myocardial ischemia. He was found to have complete occlusion of the LAD coronary artery (Fig. 2a, b), and percutaneous coronary intervention was performed with aspiration of the thrombus and suc-cessful placement of a 3 9 15-mm Vision coronary stent (Abbott Vascular, Temecula, CA). This resulted in improved angiographic flow and myocardial blush (Fig. 2c). The right coronary artery appeared to be normal. The myocardial band enzymes of creatine phosphokinase (CPK-MB) trended down, whereas the troponin 1 level peaked after stent placement (Table 1).

Fig. 1 a Electrocardiogram (ECG) at initial presentation showing a Q-wave pattern in lead V6 and ST segment depression in inferior leads with ST segment elevation in reciprocal leads. b Resolution of QS pattern in lead V6 with persistent abnormal precordial R-wave progression, ST segment depression in the inferior leads, and ST segment elevation in reciprocal leads consistent with an infarct pattern

A peripheral blood smear showed pancytopenia with 38 % hypergranular blast-like cells consistent with acute myeloid leukemia (AML). Chemotherapy with all-trans-retinoic acid (ATRA) was implemented. Despite bleeding risk, antiplatelet therapy with aspirin and Plavix was ini-tiated for stent thrombosis prophylaxis, and enalapril and metoprolol were initiated for afterload reduction and myocardial protection.

At the time of discharge, 3 months after admission, the boy had complete resolution of chest pain and coagulopa-thy with normalization of fibrinogen levels, platelet count, and cardiac enzymes (Table 1). With initiation of chemo-therapy, the white blood cell (WBC) count was normal at discharge. A bone marrow biopsy confirmed a diagnosis of acute promyelocytic leukemia (APML), a type of AML, and complete induction with arsenic trioxide and gem-tuzumab was initiated. The boy went on to complete his induction therapy without further significant complications, and his WBC had normalized by discharge.

A follow-up echocardiogram showed regional wall motion abnormalities, with mild left ventricular dilation

Table 1 Important laboratory data at different stages of clinical course: admission, after stent placement and discharge. Abnormalities are seen in cardiac markers, coagulation studies and complete blood count but all laboratory studies are normal at discharge

Admission After stent placement At discharge
CPK-MB (B9.9 ng/mL) 266 36.4 1.6
Troponin-I (B0.045 ng/mL) 28.4 82.3 \0.04
Fibrinogen (200–400 mg/dL) 86 111 342
PT/INR (11.8–14.1 s/0.8–1.2) 1.5/18.7 1.4/18 0.96/13.3
D-dimer (Blg/mL) [20 [20 1
WBC (4.5–13 K/lL) 3.9 3.5 7.6
Platelets (135–466 K/lL) 27,000 55,000 210,000
Blasts % 38 19 1

CPK-MB myocardial band enzymes of creatine phosphokinase, PT prothrombin time, INR international normalized ratio, WBC white blood cell count

Fig. 2 a, b Cardiac catheterization showing that the left main coronary artery is quite short and branches immediately into the left circumflex coronary artery and the left anterior descending (LAD) coronary. After the first diagonal branch, the LAD coronary artery is noted to be completely occluded (arrow), with no distal flow

observed. c Significantly improved filling in the left LAD coronary artery (arrow). The filling defect within the stent is almost completely resolved, but the distal portion of the LAD remains irregular in nature and quite thin. Improved filling also is noted in the distal perforating branches of the LAD coronary artery

Fig. 3 Cardiac magnetic resonance imaging (MRI) myocardial delayed enhancement (MDE) sequence. The black represents normal tissue, and the white denotes areas of MDE, indicated by the red arrows. a Four-chamber plane, b three-chamber plane, c short axis as the base, d short axis at the midventricle, e short axis at the apex. There is transmural and subendocardial myocardial delayed hyperenhancement consistent with left anterior descending and circumflex coronary artery distribution

and an ejection fraction (EF) of 44 % (normal 55–65 %). Cardiac magnetic resonance imaging (MRI) 3 months later showed mildly depressed global systolic function with significant hypokinesis of segments of the myocardial wall consistent with the LAD and circumflex coronary artery distributions, with the coronary stent in good position and patent. Significant myocardial delayed enhancement (MDE) abnormalities suggested subendocardial and trans-mural fibrosis (Fig. 3a–e).

Discussion

To the best of our knowledge, this is the first pediatric case report of an AML-associated AMI, and it emphasizes the benefit resulting from expedient reperfusion of the ische-mic myocardium. It also highlights the importance of an in-depth evaluation for the potential etiology. In contrast to the adult population, the etiology is unlikely to be associ-ated with atherosclerotic coronary artery disease. The incidence of AMIs among adolescents is low and estimated to be 6.6 per 1 million patient-years [3].

In pediatrics, AMIs can be caused by a multitude of abnormalities secondary to both primary cardiac disease and non-cardiac diseases. Cardiac diagnoses at high risk for coronary ischemia include Kawasaki disease, anatomic coronary abnormalities, and myocarditis. Non-cardiac

diseases include systemic lupus erythematosus, sickle cell disease, and hypercoagulable states such as occur with various oncologic processes [4].

The cancer diagnosis most commonly associated with coagulation abnormalities is APML, a unique form of AML that may manifest with either thrombosis (*10 % of patients) [2] or hemorrhage at the time of diagnosis. In the reported patient, the hypercoagulable state that resulted from the abnormal promyelocytes led to an in situ thrombus formation in the LAD. Much debate in the adult literature focuses on the utility of revasculari-zation for complete occlusion of a large branch of the left coronary artery system if there is little viable myo-cardium [1].

In the reported case, we did not have pre-intervention viability imaging. Percutaneous coronary intervention provided the most rapid reperfusion possible, and we were able to minimize the boy’s chance of cardiopulmonary bypass-associated complications that may have occurred with an open approach. With rapid percutaneous coronary intervention, the boy survived free of end-organ dysfunc-tion and with minimal long-term cardiac sequelae. Despite his cardiac MRI images demonstrating significant fibrosis by MDE, he has tolerated his chemotherapy regimen and many neutropenia-associated infections without evidence of hemodynamic compromise. The discrepancy between the fibrosis seen on MRI and his clinical status is presumed to be due to favorable remodeling that may be more likely to occur in this young age group. Adult experience may guide our management of AMI in pediatrics but may not be accurate in predicting the outcome for children.

We hypothesize that the reported patient’s myocardial infarction was secondary to in situ clot formation on a damaged endothelial surface, and although regional wall motion abnormalities and delayed enhancement were seen on follow-up imaging, he is currently clinically doing well and tolerating treatment of his AML.

Conflict of interest

There are no conflicts of interest to disclose.

References

  1. Ammirati E, Rimoldi OE, Camici PG (2011) Is there evidence supporting coronary revascularization in patients with left ventricular systolic dysfunction? Circ J 75:3–10
  2. De Stefano V, Sora F, Rossi E, Chiusolo P, Laurenti L, Fianchi L, Zini G, Pagano L, Sica S, Leone G (2005) The risk of thrombosis in patients with acute leukemia: occurrence of thrombosis at diagnosis and during treatment. J Thromb Haemost 3:1985–1992
  3. Mahle WT, Campbell RM, Favaloro-Sabatier J (2007) Myocardial infarction in adolescents. J Pediatr 151:150–154
  4. Reich JD, Campbell R (1998) Myocardial infarction in children. Am J Emerg Med 16:296–303

 

1 Comment
  1. Ivy Torres says

    Hi, this is a comment.
    To get started with moderating, editing, and deleting comments, please visit the Comments screen in the dashboard.

Comments are closed.