Table 1 Suggested risk stratification... | American Society of Hematology

Table 1

Suggested risk stratification for perioperative thromboembolism⁷

Risk category	MHV	Atrial fibrillation	VTE
High (> 10%/y risk of ATE or > 10%/mo risk of VTE)	Any mechanical mitral valve	CHADS₂ score of 5 or 6	Recent (< 3 mo) VTE
	Caged-ball or tilting disc valve in mitral/aortic position	Recent (< 3 mo) stroke or TIA	Severe thrombophilia
			Deficiency of protein C, protein S or antithrombin
	Recent (< 6 mo) stroke or TIA	Rheumatic valvular heart disease	Antiphospholipid antibodies
			Multiple thrombophilias
Intermediate (4%-10%/y risk of ATE or 4%-10%/mo risk of VTE)	Bileaflet AVR with major risk factors for stroke	CHADS₂ score of 3 or 4	VTE within past 3-12 mo
			Recurrent VTE
			Nonsevere thrombophilia
			Active cancer
Low (< 4%/y risk of ATE or < 2%/mo risk of VTE)	Bileaflet AVR without major risk factors for stroke	CHADS₂ score of 0-2 (and no prior stroke or TIA)	VTE > 12 mo ago

Risk category	MHV	Atrial fibrillation	VTE
High (> 10%/y risk of ATE or > 10%/mo risk of VTE)	Any mechanical mitral valve	CHADS₂ score of 5 or 6	Recent (< 3 mo) VTE
	Caged-ball or tilting disc valve in mitral/aortic position	Recent (< 3 mo) stroke or TIA	Severe thrombophilia
			Deficiency of protein C, protein S or antithrombin
	Recent (< 6 mo) stroke or TIA	Rheumatic valvular heart disease	Antiphospholipid antibodies
			Multiple thrombophilias
Intermediate (4%-10%/y risk of ATE or 4%-10%/mo risk of VTE)	Bileaflet AVR with major risk factors for stroke	CHADS₂ score of 3 or 4	VTE within past 3-12 mo
			Recurrent VTE
			Nonsevere thrombophilia
			Active cancer
Low (< 4%/y risk of ATE or < 2%/mo risk of VTE)	Bileaflet AVR without major risk factors for stroke	CHADS₂ score of 0-2 (and no prior stroke or TIA)	VTE > 12 mo ago

TIA indicates transient ischemic attack; AVR, aortic valve replacement; ATE, arterial thromboembolism; VTE, venous thromboembolism; and MHV, mechanical heart valve.