Baseline characteristics of intervention trial subjects*
| Characteristic . | Sildenafil (n = 37) . | Placebo (n = 37) . | P† . |
|---|---|---|---|
| Age, y | 47 ± 13 | 44 ± 14 | .33 |
| Female sex, % | 62 | 62 | > .999 |
| Black, % | 97 | 100 | > .999 |
| Not Hispanic, % | 87 | 100 | .05 |
| SCD genotype, SS/SC/SB+ or SB0/other,‡ % | 84/13/0/3 | 76/22/3/0 | .45 |
| 6MWD distance, m | 381 ± 75 | 386 ± 75 | .76 |
| Tricuspid regurgitant jet velocity, m/s | 3.0 ± 0.5 | 3.0 ± 0.3 | .38 |
| NT-proBNP, pg/L | 527 ± 852 | 243 ± 367 | .03§ |
| NT-proBNP, log10 | 2.3 ± 0.6 | 2.0 ± 0.6 | .03 |
| BDS | 2.5 ± 2.10 | 2.1 ± 2.02 | .33 |
| NYHA functional class (I/II/III/IV), % | 32/41/27/0 | 40/38/22/0 | .77 |
| Left ventricular ejection fraction, % | 61 ± 6 | 62 ± 6 | .56 |
| Blood pressure, mmHg | |||
| Systolic | 125 ± 21 | 119 ± 13 | .18 |
| Diastolic | 69 ± 11 | 70 ± 9 | .69 |
| Heart rate, bpm | 74 ± 13 | 78 ± 10 | .11 |
| Oxygen saturation, % | 95 ± 4 | 96 ± 3 | .27 |
| Body surface area, m2 | 1.87 ± 0.34 | 1.84 ± 0.21 | .70 |
| Current smoking, % | 16 | 14 | .89 |
| History of hydroxyurea therapy, % | 57 | 70 | .33 |
| Hydroxyurea dosing-current, mg/kg (n) | 8.7 ± 7.9 (12) | 6.8 ± 9.0 (12) | .62 |
| History of acute chest syndrome, % | 62 | 70 | .62 |
| History of asthma, % | 16 | 38 | .07 |
| On chronic transfusion therapy, % | 5 | 8 | > .999 |
| > 20 blood transfusions during lifetime, % | 41 | 41 | > .999 |
| History of priapism, % of men | 14 | 14 | > .999 |
| Hemoglobin, g/dL | 8.1 ± 1.6 | 8.7 ± 1.6 | .07 |
| White blood cell count, ×103/μL | 9.0 ± 3.4 | 9.0 ± 3.6 | .95 |
| Platelet count, ×103/μL | 344 ± 120 | 328 ± 110 | .57 |
| Blood urea nitrogen, mg/dL | 15 ± 11 | 11 ± 6 | .29 |
| Creatinine, mg/dL | 1.0 ± 0.5 | 0.8 ± 0.3 | .04 |
| Total bilirubin, mg/dL | 3.1 ± 2.6 | 3.3 ± 2.4 | .64 |
| Alkaline phosphatase, U/L | 98 ± 47 | 104 ± 52 | .39 |
| Alanine aminotransferase, U/L | 22 ± 12 | 25 ± 18 | .40 |
| Aspartate aminotransferase, U/L | 44 ± 27 | 45 ± 25 | .90 |
| Lactate dehydrogenase, IU/L | 491 ± 293 | 482 ± 348 | .75 |
| Characteristic . | Sildenafil (n = 37) . | Placebo (n = 37) . | P† . |
|---|---|---|---|
| Age, y | 47 ± 13 | 44 ± 14 | .33 |
| Female sex, % | 62 | 62 | > .999 |
| Black, % | 97 | 100 | > .999 |
| Not Hispanic, % | 87 | 100 | .05 |
| SCD genotype, SS/SC/SB+ or SB0/other,‡ % | 84/13/0/3 | 76/22/3/0 | .45 |
| 6MWD distance, m | 381 ± 75 | 386 ± 75 | .76 |
| Tricuspid regurgitant jet velocity, m/s | 3.0 ± 0.5 | 3.0 ± 0.3 | .38 |
| NT-proBNP, pg/L | 527 ± 852 | 243 ± 367 | .03§ |
| NT-proBNP, log10 | 2.3 ± 0.6 | 2.0 ± 0.6 | .03 |
| BDS | 2.5 ± 2.10 | 2.1 ± 2.02 | .33 |
| NYHA functional class (I/II/III/IV), % | 32/41/27/0 | 40/38/22/0 | .77 |
| Left ventricular ejection fraction, % | 61 ± 6 | 62 ± 6 | .56 |
| Blood pressure, mmHg | |||
| Systolic | 125 ± 21 | 119 ± 13 | .18 |
| Diastolic | 69 ± 11 | 70 ± 9 | .69 |
| Heart rate, bpm | 74 ± 13 | 78 ± 10 | .11 |
| Oxygen saturation, % | 95 ± 4 | 96 ± 3 | .27 |
| Body surface area, m2 | 1.87 ± 0.34 | 1.84 ± 0.21 | .70 |
| Current smoking, % | 16 | 14 | .89 |
| History of hydroxyurea therapy, % | 57 | 70 | .33 |
| Hydroxyurea dosing-current, mg/kg (n) | 8.7 ± 7.9 (12) | 6.8 ± 9.0 (12) | .62 |
| History of acute chest syndrome, % | 62 | 70 | .62 |
| History of asthma, % | 16 | 38 | .07 |
| On chronic transfusion therapy, % | 5 | 8 | > .999 |
| > 20 blood transfusions during lifetime, % | 41 | 41 | > .999 |
| History of priapism, % of men | 14 | 14 | > .999 |
| Hemoglobin, g/dL | 8.1 ± 1.6 | 8.7 ± 1.6 | .07 |
| White blood cell count, ×103/μL | 9.0 ± 3.4 | 9.0 ± 3.6 | .95 |
| Platelet count, ×103/μL | 344 ± 120 | 328 ± 110 | .57 |
| Blood urea nitrogen, mg/dL | 15 ± 11 | 11 ± 6 | .29 |
| Creatinine, mg/dL | 1.0 ± 0.5 | 0.8 ± 0.3 | .04 |
| Total bilirubin, mg/dL | 3.1 ± 2.6 | 3.3 ± 2.4 | .64 |
| Alkaline phosphatase, U/L | 98 ± 47 | 104 ± 52 | .39 |
| Alanine aminotransferase, U/L | 22 ± 12 | 25 ± 18 | .40 |
| Aspartate aminotransferase, U/L | 44 ± 27 | 45 ± 25 | .90 |
| Lactate dehydrogenase, IU/L | 491 ± 293 | 482 ± 348 | .75 |
Percentages are based on the number of subjects (n) in a given group for the population analyzed. ± values are means ± SD. Log values (on a base 10 scale) were used to analyze laboratory measurements.
For categorical variables, treatment group differences were assessed using a Fisher exact test. For age, TRV, NT-proBNP, 6MWD, hemoglobin electrophoresis, and BDS treatment group differences were assessed via t test. For left ventricular ejection fraction and other laboratory values, treatment group differences were assessed via ANOVA including stratum.
SB+ or SB0 = S beta+ thalassemia or S beta0 thalassemia, respectively.
This analysis is of the log10 value and is a duplicate of the one noted in the next line of the table. Because the actual values were especially nonnormal, we have reported the transformed means ± SD as well as the original.