Cardiac Complications in Thrombotic Thrombocytopenic Purpura: Data from Nationwide Inpatient Sample
Authors: Pathak Ranjan , Aryal Madan Raj , Giri Smith , Karmacharya Paras , Donato Anthony A 
Published: November 2019

Background

Thrombotic thrombocytopenic Purpura (TTP) has been reported to be associated with serious cardiac complications including arrhythmia, sudden cardiac death, myocardial infarction, cardiogenic shock, and heart failure. These complications are believed to be the sequelae of diffuse platelet thrombi leading to infarction in cardiac tissue. However, the true burden of cardiac complications in TTP in clinical practice remains unclear.

Methods

We used the 2009-2011 Nationwide Inpatient Sample database to identify hospitalizations in patients ≥18 years with a diagnosis of TTP (International Classification of Diseases, 9th revision, Clinical Modification [ICD-9-CM] code 446.6. Nationwide Inpatient Sample is the largest all-payer publicly available inpatient care database in the US. It contains data from five to eight million hospital stays from about 1,000 hospitals across the country and approximates a 20% sample of all US hospitals. ICD-9-CM codes were used to identify any of the following coded cardiac complications- 1) arrhythmias, 2) acute myocardial infarction (MI), 3) cardiogenic shock, 4) acute heart failure, and 5) conduction abnormalities. Univariate and multivariate logistic regression was used to determine the odds of various cardiac complications in patients with TTP compared to patients without TTP. Univariate analysis was done to compare baseline demographic and hospital characteristics between patients among TTP patients with and without cardiac complications. Data analysis was done using STATA version 13.0 (College Station, TX).

Results

Of the estimated total 4,367 TTP hospitalizations, 22.2 % (n=969) developed at least 1 of the above cardiac complications. Mean age of our cohort was 56.2±17.3, with the majority of patients being white (55.1%). Compared to those with TTP and no reported cardiac events, dyslipidemia (p=0.01) hypertension (p=0.001), peripheral vascular disease (p=0.03), acute kidney injury (p<0.001), chronic kidney disease (p=0.003), stroke (p=0.01), sepsis (p=0.01) and coronary artery disease (p<0.001) were more likely in patients with cardiac complications (Table 1). On multivariate analysis, patients with TTP were found to develop acute MI more commonly than patients without TTP (OR 5.22, 95% CI 3.81-7.15; p<0.001). Interestingly, acute heart failure was found to be less common in TTP patients (OR 0.7, 95% CI 0.55-0.90; p=0.002). There was no significant difference in the incidence of arrhythmias, cardiogenic shock and conduction disorders among patients with TTP compared to patient without TTP (Figure 1).

Conclusion

In this study of large national database, acute MI was found to be the most common cardiac complication in patients with TTP. Although reported, arrhythmias, cardiogenic shock and conduction disorders were not significantly associated with TTP.

Table Characteristic TTP without Cardiac Complications (n=3,398) TTP with Cardiac Complications (n=969) p Age, mean ± SD 44.5±15.2 56.2±17.3 <0.001 Sex 0.094 Male 31.3 38.7 Female 68.7 61.3 Race 0.009 White 41.8 55.1 Black 45.1 33.5 Hispanic 8.3 4 Asian or Pacific Islander 1.1 3.5 Native American 0.7 0.6 Other 3 3.3 Primary Payer <0.001 Medicare 18.9 37.8 Medicaid 23.9 14.9 Private insurance 42.4 37.4 Self-pay 10.1 5 No charge 0.7 2 Other 4 2.9 Region 0.520 Northeast 15.6 18.2 Midwest 26.7 27.9 South 45.6 39.5 West 12.1 14.4 Comorbidities Smoking 26.8 26.2 0.871 Obesity 12.1 9.1 0.210 Dyslipidemia 13.2 21.9 0.009 Hypertension 50.3 62.9 0.001 DM 23.5 27.9 0.227 PVD 1.1 4.4 0.029 CAD 5.1 15.4 <0.001 AKI 35.5 61.1 <0.001 CKD 16.5 27.3 0.003 Stroke 4.9 11.8 0.007 Sepsis 3.9 9.7 0.01

AKI = Acute Kidney Injury; CAD = Coronary Artery Disease; CKD = Chronic Kidney Disease; DM = Diabetes Mellitus; PVD = Peripheral Vascular Disease

Figure 1. Multivariate analysis of Cardiac Complications in TTP Figure 1. Multivariate analysis of Cardiac Complications in TTP

Disclosures

No relevant conflicts of interest to declare.