Myocardial infarction in thrombotic thrombocytopenic purpura: a single-center experience and literature review

Concurrent myocardial infarction in the setting of thrombotic thrombocytopenic purpura secondary to systemic lupus erythematosus: A case report

Key Clinical Message

In acute thrombotic thrombocytopenic purpura (TTP), apart from urgent treatment, assessing the patient's medical history, especially conditions like systemic lupus erythematosus that could trigger TTP, is crucial. Rarely, TTP patients may experience cardiac conditions as severe as a myocardial infarction.

Abstract

A 45-year-old woman manifested severe and acute thrombotic thrombocytopenic purpura (TTP) of unknown origin. The patient's symptoms, the laboratory data, the detection of the reduction in ADAMTS13 activity, and the presence of schistocytes on the peripheral smear confirmed the diagnosis. The patient was then planned for therapeutic plasma exchange (TPE). Prior to the scheduled TPE, she suddenly experienced extreme shortness of breath and chest pain. An electrocardiogram was obtained immediately after reporting signs of an inferior myocardial infarction. Further examinations to acquire information about the patient's underlying medical conditions in order to study the secondary causes of TTP, combined with the results of the laboratory tests, resulted in the patient being diagnosed with systemic lupus erythematosus.

Laboratory investigation and diagnosis of thrombotic thrombocytopenic purpura

Thrombotic thrombocytopenic purpura (TTP) is a rare and potentially fatal disease for which rapid diagnosis is crucial for patient outcomes. Deficient activity (< 10%) of the liver enzyme, ADAMTS13, is the pathophysiological hallmark of TTP, and measurement of the enzyme activity can establish the diagnosis of TTP with high accuracy. Thus, along with the clinical history, appropriate laboratory assessment of a suspected case of TTP is essential for diagnosis and treatment. Here, we present a review of the available laboratory tests that can assist clinicians in establishing the diagnosis of TTP, with special focus on ADAMTS13 assays, including the measurement of the antigen and activity, and detection of autoantibodies to ADAMTS13.

Cardiovascular Disease and Stroke in Immune TTP-Challenges and Opportunities

Advances in the management of immune thrombotic thrombocytopenic purpura (iTTP) have dramatically improved outcomes of acute TTP episodes, and TTP is now treated as a chronic, relapsing disorder. It is now recognized that iTTP survivors are at high risk for vascular disease, with stroke and myocardial infarction occurring at younger ages than in the general population, and cardiovascular disease is the leading cause of premature death in this population. iTTP appears to have a phenotype of accelerated vascular aging with a particular predilection for cerebral circulation, and stroke is much more common than myocardial infarction. In addition to traditional cardiovascular risk factors, low ADAMTS13 activity during clinical remission may be a risk factor for some of these outcomes, such as stroke. Recent studies also suggest that Black patients, who are disproportionately affected by iTTP in the United States, are at higher risk of adverse cardiovascular outcomes, likely due to multifactorial reasons. Additional research is required to establish the risk factors and mechanisms underlying these complications in order to institute optimal screening strategies and identify interventions to improve outcomes.

A Case of Thrombotic Thrombocytopenic Purpura and ST-Elevation Myocardial Infarction: An Unusual Correlation

Thrombotic thrombocytopenic purpura (TTP) is a rare and potentially devastating blood disorder depicted by thrombocytopenia, fever, widespread small vessel hemolytic anemia, and neurological symptoms. The involvement of the renal and neurological systems is frequently reported in TTP; however, TTP-induced acute coronary syndrome is not widely reported. We describe a case of myocardial infarction induced by TTP in a patient who presented with the typical manifestation of acute coronary syndrome. Echocardiogram revealed a myocardial injury, and detailed investigations revealed increased levels of troponin I, lactate dehydrogenase, diminished levels of haptoglobin and von Willebrand factor-cleaving protease, and schistocytes on peripheral smear, suggestive of TTP-induced myocardial infarction. His condition was stabilized after commencing plasmapheresis, steroids, and rituximab. The initial steps in the management of this patient involve the prompt administration of steroids and the urgent start of plasmapheresis to increase platelet count.

Non-ST-Segment Elevation Myocardial Infarction As Initial Thrombotic Event of Thrombotic Thrombocytopenic Purpura: A Rare Challenging Case

Thrombotic thrombocytopenic purpura (TTP) is a rare autoimmune and devastating blood disorder that results in micro-clots throughout the body, leading to tissue damage and organ dysfunction resulting in widespread microangiopathic hemolytic anemia, thrombocytopenia, fever, and neurological symptoms. TTP patients commonly manifest renal and neurological symptoms; however, cardiovascular involvement is not widely reported in the literature. We report a case of non-ST-segment elevation myocardial infarction (NSTEMI) as an initial manifestation of TTP. Although rare, TTP complications must be considered among other possible causes of unexpected thrombocytopenia during acute phase treatment of acute coronary syndrome because of high morbidity and mortality.

Cardiovascular Complications and Their Association With Mortality in Patients With Thrombotic Thrombocytopenic Purpura

BACKGROUND

Despite widespread availability of plasmapheresis, the mortality in thrombotic thrombocytopenic purpura remains high. Cardiovascular complications have been reported as an important cause of morbidity in these patients. The burden and prognostic implications of these complications have not been well studied. We analyzed the rates of cardiovascular complications in thrombotic thrombocytopenic purpura, temporal trends, and studied its impact on in-hospital mortality.

METHODS

We analyzed the National Inpatient Sample (NIS) from January 2005 to September 2015 to identify adult patients with thrombotic thrombocytopenic purpura. This group was further refined by excluding patients who did not receive therapeutic plasmapheresis, and other conditions that can mimic thrombotic thrombocytopenic purpura. We identified the age- and sex-stratified rates of cardiac arrhythmias, cardiac conduction system disorders, heart failure, acute coronary syndrome, myocarditis, pericarditis, takotsubo cardiomyopathy, cardiogenic shock, cardiac arrest, and stroke. We also compared in-hospital mortality with and without cardiovascular complications.

RESULTS

Among 15,054 thrombotic thrombocytopenic purpura hospitalizations (mean age 46.4 years, 69% in the 18- to 54-age group, 66.2% women, and 42.9% white), a cardiovascular complication was observed in 3802 (25.3%) hospitalizations. The following cardiovascular complications were identified: stroke (10.4%), heart failure (8.3%), acute coronary syndrome (6.4%), atrial tachyarrhythmia (5.9%), ventricular tachyarrhythmia (2.0%), cardiogenic shock (0.5%), takotsubo cardiomyopathy (0.1%), atrioventricular block (0.2%), myocarditis or pericarditis (0.3), and cardiac arrest (1.9%). Rates of several cardiovascular complications were significantly higher in patients 55 years or older compared to a younger age group, whereas males had higher rates of acute coronary syndrome and tachyarrhythmias compared to females. Overall, the cardiovascular complication rate was stable during the study period. The presence of a major cardiovascular complication was associated with a significantly higher in-hospital mortality (19.7%) as compared with no major cardiovascular complication (4.1%) (adjusted odds ratio 2.09, 95% confidence interval 1.41-3.09, P <0.001). Results were generally consistent in age and sex subgroups.

CONCLUSION

Cardiovascular complications were frequently observed at a rate of 1 in 4 in patients hospitalized for thrombotic thrombocytopenic purpura and were associated with substantially higher in-hospital mortality. These findings underscore the need to promptly identify and treat these complications to improve outcomes.

[Diagnosis of thrombotic thrombocytopenic purpura]

Thrombotic thrombocytopenic purpura (TTP) is a rare, life-threatening disease, disease, characterised by microangiopathic hemolytic anaemia, consumption thrombocytopenia, and organ dysfunction. The pathogenesis of TTP is attributed to the deficiency in the activity of the metalloproteinase ADAMTS13, specific von Willebrand factor cleaving protease. TTP is suspected when detecting microangiopathic hemolytic anemia, thrombocytopenia, damage to various organs. Diagnosis of TTP is confirmed by the detection of ADAMTS13 activity in plasma less than 10%. Plasma samples for the study of ADAMTS13 activity should be taken before the start of plasma transfusions or plasma exchange. In patients with severe ADAMTS-13 deficiency autoantibodies anti-ADAMTS13 and inhibitor ADAMTS13 should be investigated. Anti-ADAMTS13 antibodies belonging to IgG not always have inhibitory effects. The inhibitory effect of anti-ADAMTS13 antibodies is confirmed by mixing test. All patients with the first established diagnosis of TTP should be examined for mutations of the ADAMTS13 gene.

Describing the point prevalence and characteristics of venous thromboembolism in patients with thrombotic thrombocytopenic purpura

BACKGROUND

Arterial thromboembolic events are relatively common and well-described in patients with thrombotic thrombocytopenic purpura (TTP). However, the literature describing venous thromboembolism (VTE) in TTP is scarce.

METHODS

Single-institution retrospective chart review was conducted in TTP patients over a 10-year period to describe the point prevalence of VTE. Data were analyzed using descriptive statistics.

RESULTS

We identified 77 consecutive patients with 123 episodes of TTP. Of these patients, 14 (18%) experienced 16 VTEs (6 pulmonary embolisms, 6 deep vein thromboses, 4 superficial vein thromboses [SVT]). Excluding SVT, the point prevalence of VTE was 14%. All were acute and associated with admission for acute TTP. All patients were treated with plasma exchange (PLEX); 6/8 patients on concurrent PLEX at VTE diagnosis were exchanged with solvent-detergent plasma (SDP). Platelet and lactate dehydrogenase levels at time of VTE diagnosis had largely normalized from presentation values (median 175 × 109 U/L [interquartile range 130.75, 250] and 232 U/L [interquartile range 178.75, 263.5], respectively). Most VTEs (9/16) occurred while patients were not on pharmacologic thromboprophylaxis. All but one VTE was treated with anticoagulation. No VTEs were fatal or massive.

CONCLUSIONS

Our data provide additional evidence that TTP patients may be at risk for VTE. It is possible that SDP exerted a prothrombotic effect. TTP-associated VTEs may be pathophysiologically distinct from arterial thromboses because they occur following hematological recovery. VTE thromboprophylaxis was not commonly used. Our findings suggest the need to implement VTE thromboprophylaxis earlier in hospitalized patients with TTP.

Atypical Hemolytic Uremic Syndrome Presenting as Acute Heart Failure-A Rare Presentation: Diagnosis Supported by Skin Biopsy

Atypical hemolytic uremic syndrome (aHUS) is a rare disorder of uncontrolled complement activation that manifests classically as anemia, thrombocytopenia, and renal failure, although extrarenal manifestations are observed in 20% of the patient most of which involving central nervous system, with relatively rare involvement of the heart. In this article, we report the case of a 24-year-old male with no history of heart disease presenting with acute systolic heart failure along with microangiopathic hemolytic anemia, thrombocytopenia, and acute kidney injury. Given his presentation of thrombotic microangiopathy (TMA), along with laboratory results significant for low haptoglobin, platelets, hemoglobin, C3, C4, CH50, and normal ADAMTS13 levels, with no diarrhea and negative STEC polymerase chain reaction in stool, aHUS diagnosis was established with strong clinical suspicion, and immediate initiation of treatment was advised. Kidney biopsy to confirm diagnosis of aHUS was inadvisable because of thrombocytopenia, so the skin biopsy of a rash on his arm was done, which came to be consistent with thrombotic microangiopathy. Our case highlights a relatively rare association between aHUS and cardiac involvement, and the use of skin biopsy to support diagnosis of aHUS in patients who cannot undergo renal biopsy because of thrombocytopenia.

Cardiac implications of thrombotic thrombocytopenic purpura

Thrombotic thrombocytopenic purpura (TTP) is a multisystem disorder that essentially can affect any organ in the human body. The hallmark of the pathogenesis in TTP is the large von Willebrand factor multimers on platelet-mediated micro-thrombi formation, leading to microvascular thrombosis. Autopsy studies showed that cardiac arrest and myocardial infarction are the most common immediate causes of death in these patients. Clinical manifestations of cardiac involvement in TTP vary dramatically, from asymptomatic elevation of cardiac biomarkers, to heart failure, MI and sudden cardiac death. There is limited knowledge about optimal cardiac evaluation and management in patients with TTP. The absence of typical cardiac symptoms, combined with complicated multi-organ involvement in TTP, may contribute to the under-utilization of cardiac evaluation and treatment. Prompt diagnosis and timely initiation of effective therapy could be critically important in selected cases. Based on our experience and this review of the literature, we developed several recommendations for focused cardiac evaluation for patients with acute TTP: (1) patients with suspected or confirmed TTP should be screened for the potential presence of cardiac involvement with detailed history and physical, electrocardiogram and cardiac enzymes; (2) clinical deterioration of TTP patients warrants immediate cardiac reevaluation; (3) TTP patients with clinical evidence of cardiac involvement should be monitored for telemetry, cardiac biomarkers and evaluated with transthoracic echocardiography. These patients require urgent targeted TTP treatment as well as cardiac-specific treatment. Aspirin therapy is indicated for all TTP patients. Since epicardial coronary artery involvement is rare, cardiac catheterization is usually not required, given the high risk for hemorrhage and kidney injury; (4) we recommend evidence-based medical therapy for ischemic symptoms and heart failure. TTP patients with evidence of cardiac involvement would also benefit from routine cardiology follow up during remission.

TTP-like syndrome: novel concept and molecular pathogenesis of endotheliopathy-associated vascular microthrombotic disease

TTP is characterized by microangiopathic hemolytic anemia and thrombocytopenia associated with brain and kidney dysfunction. It occurs due to ADAMTS13 deficiency. TTP-like syndrome occurs in critically ill patients with the similar hematologic changes and additional organ dysfunction syndromes. Vascular microthrombotic disease (VMTD) includes both TTP and TTP-like syndrome because their underlying pathology is the same disseminated intravascular microthrombosis (DIT). Microthrombi are composed of platelet-unusually large von Willebrand factor multimers (ULVWF) complexes. TTP occurs as a result of accumulation of circulating ULVWF secondary to ADAMTS13 deficiency. This protease deficiency triggers microthrombogenesis, leading to "microthrombi" formation in microcirculation. Unlike TTP, TTP-like syndrome occurs in critical illnesses due to complement activation. Terminal C5b-9 complex causes channel formation to endothelial membrane, leading to endotheliopathy, which activates two different molecular pathways (i.e., inflammatory and microthrombotic). Activation of inflammatory pathway triggers inflammation. Activation of microthrombotic pathway promotes platelet activation and excessive endothelial exocytosis of ULVWF from endothelial cells (ECs). Overexpressed and uncleaved ULVWF become anchored to ECs as long elongated strings to recruit activated platelets, and assemble "microthrombi". In TTP, circulating microthrombi typically be lodged in microvasculature of the brain and kidney, but in TTP-like syndrome, microthrombi anchored to ECs of organs such as the lungs and liver as well as the brain and kidneys, leading to multiorgan dysfunction syndrome. TTP occurs as hereditary or autoimmune disease and is the phenotype of ADAMTS13 deficiency-associated VMTD. But TTP-like syndrome is hemostatic disorder occurring in critical illnesses and is the phenotype of endotheliopathy-associated VMTD. Thus, this author's contention is TTP and TTP-like syndrome are two distinctly different disorders with dissimilar underlying pathology and pathogenesis.

Myocardial Infarction as an Early Presentation in Thrombotic Thrombocytopenic Purpura: A Rare Case Series

Renal and neurological involvements are frequently seen in thrombotic thrombocytopenic purpura (TTP). Cardiac involvement, however, has been rarely reported. In this article, we present 2 cases of myocardial infarction in patients with TTP. In the first case, a young man presented with non-ST-segment elevation myocardial infarction that resolved promptly with plasmapheresis. The second patient developed ST-segment elevation myocardial infarction early in the course of the disease and died before plasmapheresis could be initiated. Hence, a high degree of suspicion with prompt diagnosis and treatment is needed to prevent mortality associated with cardiac involvement in TTP.

[Pulmonary tumor thrombotic microangiopathy]

Pulmonary tumor thrombotic microangiopathy syndrome is a rare clinicopathological entity in which tumor cell micro-emboli in the pulmonary microcirculation induced thrombotic microangiopathy. This can cause respiratory failure, and acute or sub-acute right heart failure. Histological features include micro tumor emboli in the small arteries and arterioles of the lung associated with thrombus formation and fibro-cellular and fibro-muscular intimal proliferation. The diagnosis is however extremely difficult to make before death. Thus, most of the observations reported are based on autopsy data. Very rare diagnostic observations made before death suggest the potential effectiveness of chemotherapy. Many details remain to be elucidated, interdisciplinary research is a priority with close collaboration between pathologists and clinicians to better understand this, often fatal, syndrome. It may be that the use of targeted therapies will improve the very poor prognosis allowing survival of several weeks or months after diagnosis.

Acute Coronary Syndromes in Patients with Hematological Disorders

Hematological conditions can lead to serious disturbances in blood rheology, being frequently associated with increased systemic inflammation and increased risk of bleeding. The imbalance between coagulation and thrombolytic factors in patients with acute coronary syndromes may lead to undesirable outcomes, and the success of emergency coronary angioplasty or by-pass grafting may be altered by increased bleeding in coagulopathies such as hemophilia. This paper intends to review the present knowledge in the field of acute coronary syndromes in subjects with hematological and onco-hematological disorders such as thrombotic thrombocytopenic purpura, immune thrombocytopenic purpura, von Willebrand disease, hemophilia, polycythemia vera, erythrocyte disorders, myelodysplastic syndrome, leukemia, lymphoma or myeloma.

Thrombotic thrombocytopenic purpura presenting as acute coronary syndrome

In patients presenting with thrombotic thrombocytopenia purpura and non‐ST elevation myocardial infarction, prompt initiation of plasma exchange takes precedence over other invasive diagnostic procedures for coronary artery disease. Such procedures should be delayed until clinical condition and laboratory parameters have been stabilized.

Caplacizumab for Acquired Thrombotic Thrombocytopenic Purpura

BACKGROUND

Acquired thrombotic thrombocytopenic purpura (TTP) is caused by aggregation of platelets on ultralarge von Willebrand factor multimers. This microvascular thrombosis causes multiorgan ischemia with potentially life-threatening complications. Daily plasma exchange and immunosuppressive therapies induce remission, but mortality and morbidity due to microthrombosis remain high.

METHODS

Caplacizumab, an anti-von Willebrand factor humanized single-variable-domain immunoglobulin (Nanobody), inhibits the interaction between ultralarge von Willebrand factor multimers and platelets. In this phase 2, controlled study, we randomly assigned patients with acquired TTP to subcutaneous caplacizumab (10 mg daily) or placebo during plasma exchange and for 30 days afterward. The primary end point was the time to a response, defined as confirmed normalization of the platelet count. Major secondary end points included exacerbations and relapses.

RESULTS

Seventy-five patients underwent randomization (36 were assigned to receive caplacizumab, and 39 to receive placebo). The time to a response was significantly reduced with caplacizumab as compared with placebo (39% reduction in median time, P=0.005). Three patients in the caplacizumab group had an exacerbation, as compared with 11 patients in the placebo group. Eight patients in the caplacizumab group had a relapse in the first month after stopping the study drug, of whom 7 had ADAMTS13 activity that remained below 10%, suggesting unresolved autoimmune activity. Bleeding-related adverse events, most of which were mild to moderate in severity, were more common with caplacizumab than with placebo (54% of patients vs. 38%). The frequencies of other adverse events were similar in the two groups. Two patients in the placebo group died, as compared with none in the caplacizumab group.

CONCLUSIONS

Caplacizumab induced a faster resolution of the acute TTP episode than did placebo. The platelet-protective effect of caplacizumab was maintained during the treatment period. Caplacizumab was associated with an increased tendency toward bleeding, as compared with placebo. (Funded by Ablynx; ClinicalTrials.gov number, NCT01151423.).

An autopsy case of myocardial infarction due to idiopathic thrombotic thrombocytopenic purpura

Thrombotic thrombocytopenic purpura (TTP) is a life-threatening disorder characterized by systemic platelet-von Willebrand factor aggregation, organ ischemia and profound thrombocytopenia. In this report, we describe an autopsy case of a 77-year-old Japanese man diagnosed with idiopathic TTP. He had no history of cardiovascular disease symptoms, such as chest pain, ST segment elevation, and elevation of cardiac enzyme levels, except arrhythmia. The patient suddenly died despite receiving many treatments. On autopsy, macroscopically and microscopically, acute and chronic myocardial infarction manifested as petechiae and fibrotic foci and covered a wide area in the myocardium, including the area near the atrioventricular node. The microthrombi in the small arterioles and capillaries were platelet thrombi, which showed positive results for periodic acid-Schiff stain and factor VIII on immunohistochemical staining. The cause of the sudden death was suspected to be myocardial infarction, including a cardiac conduction system disorder due to multiple platelet microthrombi. Asymptomatic myocardial infarction is an important cause of death in TTP. Therefore, the heart tissue, including the sinus-atrial node and the atrioventricular node, should be microscopically examined more closely in autopsy cases of patients with TTP who experienced sudden death of TTP. This report is a critical teaching case considering that its cause of sudden death may be arrhythmia due to a myocardial infarction including cardiac conduction system disorder by platelet microthrombi.

VIRTUAL SLIDES

The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/2113354005156739.

Cardiac troponin-I on diagnosis predicts early death and refractoriness in acquired thrombotic thrombocytopenic purpura. Experience of the French Thrombotic Microangiopathies Reference Center

BACKGROUND

Cardiac involvement is a major cause of mortality in patients with thrombotic thrombocytopenic purpura (TTP). However, diagnosis remains underestimated and delayed, owing to subclinical injuries. Cardiac troponin-I measurement (cTnI) on admission could improve the early diagnosis of cardiac involvement and have prognostic value.

OBJECTIVES

To assess the predictive value of cTnI in patients with TTP for death or refractoriness.

PATIENTS/METHODS

The study involved a prospective cohort of adult TTP patients with acquired severe ADAMTS-13 deficiency (< 10%) and included in the registry of the French Reference Center for Thrombotic Microangiopathies. Centralized cTnI measurements were performed on frozen serum on admission.

RESULTS

Between January 2003 and December 2011, 133 patients with TTP (mean age, 48 ± 17 years) had available cTnI measurements on admission. Thirty-two patients (24%) had clinical and/or electrocardiogram features. Nineteen (14.3%) had cardiac symptoms, mainly congestive heart failure and myocardial infarction. Electrocardiogram changes, mainly repolarization disorders, were present in 13 cases. An increased cTnI level (> 0.1 μg L(-1) ) was present in 78 patients (59%), of whom 46 (59%) had no clinical cardiac involvement. The main outcomes were death (25%) and refractoriness (17%). Age (P = 0.02) and cTnI level (P = 0.002) showed the greatest impact on survival. A cTnI level of > 0.25 μg L(-1) was the only independent factor in predicting death (odds ratio [OR] 2.87; 95% confidence interval [CI] 1.13-7.22; P = 0.024) and/or refractoriness (OR 3.03; 95% CI 1.27-7.3; P = 0.01).

CONCLUSIONS

A CTnI level of > 0.25 μg L(-1) at presentation in patients with TTP appears to be an independent factor associated with a three-fold increase in the risk of death or refractoriness. Therefore, cTnI level should be considered as a prognostic indicator in patients diagnosed with TTP.

A case of transplantation-associated thrombotic microangiopathy with cardiac involvement successfully treated with plasma exchange

Transplantation-associated thrombotic microangiopathy (TA-TMA) is occasionally described as a serious complication after allogeneic and, more rarely, autologous stem cell transplantation (SCT). It is characterized by poor outcome with high mortality rate. Plasma exchange (PE) has been reported as successful first-line therapy in other thrombotic microangiopathies. However, unlike to idiopathic forms, response to PE are usually suboptimal in TA-TMA and the use of PE remains controversial, because the exact mechanism of injury is not yet understood. The kidney is the most commonly affected organ and injury has rarely been reported elsewhere in the body, such as in lungs and gastrointestinal tract. Although several case reports have documented myocardial infarctions in patients presenting classic thrombotic thrombocytopenic purpura (TTP), there are no reports documenting cardiac involvement in TA-TMA. We describe a case of a 66-year-old man who experienced TA-TMA accompanied by cardiac ischemia after autologous SCT for multiple myeloma, successfully treated with PE. The immediate start of PE induced a complete remission of TA-TMA and disappearance of cardiac ischemic signs and symptoms except of a residual chronic renal failure.

Predictors of in-hospital mortality and acute myocardial infarction in thrombotic thrombocytopenic purpura

BACKGROUND

Despite the widespread availability of plasmapheresis as a therapy, thrombotic thrombocytopenic purpura is associated with significant morbidity and mortality. There is a paucity of data on the predictors of poor clinical outcome in this population. Acute myocardial infarction is a recognized complication of thrombotic thrombocytopenic purpura. Little is known about the magnitude of this problem, its risk factors, and its influence on mortality in patients hospitalized with thrombotic thrombocytopenic purpura.

METHODS

We used the 2001-2010 Nationwide Inpatient Sample database to identify patients aged ≥18 years with the diagnosis of thrombotic thrombocytopenic purpura (International Classification of Diseases, 9th Revision, Clinical Modification [ICD-9-CM] code 446.6) who also received therapeutic plasmapheresis (ICD-9-CM code 99.71) during the hospitalization. Patients with acute myocardial infarction were identified using the Healthcare Cost and Utilization Project Clinical Classification Software code 100. Stepwise logistic regression was used to determine independent predictors of in-hospital mortality and acute myocardial infarction in thrombotic thrombocytopenic purpura patients.

RESULTS

Among the 4032 patients (mean age 47.5 years, 67.7% women, and 36.9% white) with thrombotic thrombocytopenic purpura who also underwent plasmapheresis, in-hospital mortality was 11.1%. Independent predictors of increased in-hospital mortality were older age (odds ratio [OR] 1.03; 95% confidence interval [CI], 1.02-1.04; P <.001), acute myocardial infarction (OR 1.89; 95% CI, 1.24-2.88; P = .003), acute renal failure (OR 2.75; 95% CI, 2.11-3.58; P <.001), congestive heart failure (OR 1.66; 95% CI, 1.17-2.34; P = .004), acute cerebrovascular disease (OR 2.68; 95% CI, 1.87-3.85; P <.001), cancer (OR 2.49; 95% CI, 1.83-3.40; P <.001), and sepsis (OR 2.59; 95% CI, 1.88-3.59; P <.001). Independent predictors of acute myocardial infarction were older age (OR 1.03; 95% CI, 1.02-1.04; P <.001), smoking (OR 1.60; 95% CI, 1.14-2.24; P = .007), known coronary artery disease (OR 2.59; 95% CI, 1.76-3.81; P <.001), and congestive heart failure (OR 2.40; 95% CI, 1.71-3.37; P <.001).

CONCLUSION

In this large national database, patients with thrombotic thrombocytopenic purpura had an in-hospital mortality rate of 11.1% and an acute myocardial infarction rate of 5.7%. Predictors of in-hospital mortality were older age, acute myocardial infarction, acute renal failure, congestive heart failure, acute cerebrovascular disease, cancer, and sepsis. Predictors of acute myocardial infarction were older age, smoking, known coronary artery disease, and congestive heart failure.

ST segment elevation myocardial infarction as a presenting feature of thrombotic thrombocytopenic purpura

Myocardial infarction with ST segment elevation (STE) on electrocardiography (ECG) is a common presentation in emergency rooms across the world. Myocardial injury and necrosis are infrequently the initial presentation in patients with thrombotic thrombocytopenic purpura (TTP). A 48-year-old woman presented with STE myocardial infarction from outside hospital for primary percutaneous coronary intervention. However, her clinical picture was not consistent. Rapid evaluation revealed symptoms associated with microangiopathic hemolytic anemia, thrombocytopenia, acute kidney injury with waxing and waning mental status. A diagnosis of TTP was made with low ADAMST-13 activity. Plasmapheresis was initiated along with intravenous steroid therapy. The patient had a full recovery and went home after full recovery of left ventricular ejection fraction and normal myocardial perfusion studies. Rapid evaluation is needed to identify infrequent causes of STE myocardial infarction. As swift protocols are activated in the emergency room and catheterization laboratories to ensure quality control, it is equally important to integrate all aspects of the patient's clinical and objective data to detect unusual disease entities.

A new mouse model mimicking thrombotic thrombocytopenic purpura: correction of symptoms by recombinant human ADAMTS13

Deficiency of a disintegrin and metalloproteinase with a thrombospondin type 1 motif, member 13 (ADAMTS13), a VWF-cleaving protease, is the key factor in the pathogenesis of thrombotic thrombocytopenic purpura (TTP), a life-threatening thrombotic microangiopathy. It is well established that ADAMTS13 deficiency results in elevated plasma levels of ultra-large VWF multimers (ULVWF), which are prone to induce platelet aggregation; however, the actual trigger of TTP development remains uncertain. Here we describe a new animal model in which some TTP-like symptoms can be triggered in ADAMTS13 knockout mice by challenge with 2000 units/kg body weight of recombinant human VWF containing ULVWF multimers. Animals rapidly showed clinical symptoms and developed severe thrombocytopenia. Schistocytosis, a decrease in hematocrit, and elevated serum lactate dehydrogenase levels were observed. The heart was identified as the most sensitive target organ with rapid onset of extensive platelet aggregation in the ventricles and myocardial necrosis. Prophylactic administration of 200 units/kg recombinant human ADAMTS13 protected ADAMTS13 knockout mice from developing TTP. Therapeutic administration of 320 units/kg rhADAMTS13 reduced the incidence and severity of TTP findings in a treatment interval-dependent manner. We therefore consider this newly established mouse model of thrombotic microangiopathy highly predictive for investigating the efficacy of new treatments for TTP.

Cardiovascular manifestations in patients with thrombotic thrombocytopenic purpura: a single-center experience

BACKGROUND

Cardiovascular manifestation in patients with thrombotic thrombocytopenic purpura.

HYPOTHESIS

The aim of this study was to investigate the incidence of acute myocardial infarction (AMI), arrhythmias, congestive heart failure, and mortality in patients hospitalized for thrombotic thrombocytopenic purpura (TTP).

METHODS

Thirty-eight patients (27 women and 11 men), mean age 44 years, were hospitalized with the diagnosis of TTP confirmed by a hematologist. We investigated the incidence of AMI which developed during hospitalization for TTP. AMI was diagnosed by new electrocardiographic changes, increased serum cardiac troponin I levels, and clinical symptomatology. The patients with AMI were also monitored for development of arrhythmias during hospitalization.

RESULTS

Of the 38 patients, 8 (21%) developed new Q-wave AMI. There was no significant difference in baseline characteristics between patients who developed AMI and those who did not develop AMI. Of the 8 patients with AMI, 2 (25%) developed atrial fibrillation, 1 (13%) developed atrial flutter, 1 (13%) developed supraventricular tachycardia, and 2 (25%) developed congestive heart failure. Death occurred in 3 of 8 patients (38%) with AMI and in 1 of 30 patients (3%) without AMI (P < 0.01).

CONCLUSIONS

New Q-wave AMI developed in 21% of 38 patients hospitalized with TTP. Supraventricular tachyarrhythmias developed in 50% of 8 patients with TTP who developed AMI. Patients hospitalized for TTP should be monitored for adverse cardiac events due to the high incidence of new AMI, supraventricular tachyarrhythmias, and mortality.