Table 5.

Number and percentage of subjects with treatment-emergent SAEs

System organ class preferred term*	Sildenafil (n = 37), n %	Placebo (n = 37), n %	P†
Any treatment-emergent SAE	17 (46)	8 (22)	.02
Congenital, familial, and genetic disorder sickle cell anemia with crisis	13 (35)	5 (14)	.03
Blood and lymphatic system disorders	3 (8)	4 (11)	.69
Acute chest syndrome	1 (3)	3 (8)	.28
Anemia	2 (5)	1 (3)	.56
Infections and infestations	2 (5)	0 (0)	.16
Bronchitis	1 (3)	0 (0)	.32
Lower respiratory tract infection	1 (3)	0 (0)	.32
Metabolism and nutrition disorders
Hyperkalemia	0 (0)	2 (5)	.16
Vascular disorders	1 (3)	1 (3)	> .999
Hypertension	0 (0)	1 (3)	.32
Hypotension	1 (3)	0 (0)	.32
Cardiac disorders	1 (3)	0 (0)	.32
Atrial fibrillation	1 (3)	0 (0)	.32
Cardiac failure congestive	1 (3)	0 (0)	.32
Eye disorders
Vitreous hemorrhage	1 (3)	0 (0)	.32
General disorders and administration site conditions
Pyrexia	1 (3)	0 (0)	.32
Injury, poisoning, and procedural complications
Traumatic brain injury	1 (3)	0 (0)	.32
Psychiatric disorders
Suicide attempt	1 (3)	0 (0)	.32
Respiratory, thoracic, and mediastinal disorders
Acute pulmonary edema	1 (3)	0 (0)	.32

^*System organ class and preferred term were based on MedDRA Version 10.1. If a subject experienced more than one episode of an adverse event, the subject was counted once for that preferred term. If a subject had more than one adverse event in a system organ class, the subject was counted once for that system organ class.

^†P value corresponds to a Cochran-Mantel-Haenszel χ² test of no difference between treatments while controlling for strata.