Abstract
Introduction
The specific risk factors for left ventricular thrombus (LVT) formation on transthoracic echocardiography (TTE) independent of age, sex, and left ventricular ejection fraction (LVEF) remain uncertain.
Purpose
To conduct a propensity-matched case control study of LVT.
Methods
We queried structured TTE report data from 113,673 patients at our institution to identify individuals with LVT on TTE, 2000–2011. Cases were matched 1:1 with controls on age, sex, LVEF, inpatient/outpatient status, image quality, test year, blood pressure, heart rate, height, and weight. using propensity scores. Risk factors for LVT formation were determined using medical chart review.
Results
Over 12 years, we identified 132 patients with LVT and 132 matched controls (mean age 62.0±16.1 years, 73.1% male, mean LVEF 27.0% ± 16.0%). Cases were similar to controls across all matched variables except height (cases vs. controls, mean height 172.2±8.8 vs. 174.8±9.3 cm, p=0.03). Compared with controls, TTEs for cases were more frequently performed for the indications of myocardial infarction (MI; 28.0% vs. 9.9%, p<0.001) and source of embolism (3.8% vs. 0.0%, p=0.008). Despite no differences between cases and controls in rates of hypertension, hyperlipidemia, diabetes, and thrombophilia (Table), a history of peripheral arterial disease was associated with a 3.4-fold increased odds of LVT formation (univariate odds ratio [OR], 3.35, 1.50–7.47, p=0.003). This association persisted despite adjustment for history of MI, stroke, height, history of recent major bleeding, and receipt of percutaneous coronary intervention (PCI) (adjusted OR, 4.33, 1.66–11.29, p=0.003). On presentation, 22.0% of cases were on anticoagulation including 20.5% on warfarin, none on a direct oral anticoagulant (DOAC), and 1.5% on heparin products. Additionally, 48.5% of cases were on antiplatelet medications. Of the 27 patients on warfarin on diagnosis of LVT, 25.9% had an International Normalized Range (INR) value <2.0. All TTE parameters were similar across groups (p>0.05 for all). Of those with LVT, 54 (40.9%) had LVT resolution over a median of 4.4 (0.9 to 13.6) months.
Conclusions
In this single center, propensity-matched case-control study of individuals with LVT on TTE, a history of peripheral arterial disease was associated with a 4.3-fold increased odds of LVT formation independent of age, sex, LVEF, history of MI, stroke, or PCI. Of those with LVT, anticoagulation was used on presentation in 22.0%. Nearly half had LVT resolution within 4.4 months.
FUNDunding Acknowledgement
Type of funding sources: Public grant(s) – National budget only. Main funding source(s): The project was funded by a grant from the National, Heart, Lung, and Blood Institute (1K23HL144907 - Strom).
Risk factors for left ventricular thrombus formation on transthoracic echocardiography in a propensity-matched case control study
