A Study of the Effectiveness of Sitaxsentan Sodium in Patients With Diastolic Heart Failure

Treadmill exercise test is used to assess the functional capacity of participants with cardiac disease. Treadmill exercise test was conducted using the 2 minute incremental Naughton protocol. The Naughton protocol starts with a 2 minute warm-up. The speed of treadmill is set to 1 mile per hour (mph) and the incline is set to 0. After the warm-up, the speed is set at 2 mph for the remainder of the test. The test consists of six, 2 minute intervals. The grade starts at 0 for the first interval, and increases by 3.5 percent every 2 minutes. The change in total exercise time (in seconds) during the treadmill test was reported.

Ratio of E to E' is used as a predictor of first cardiac events. Ratio of E to E' was measured using imaging techniques based on Doppler principles. Transmitral inflow velocity was measured by Doppler echocardiography (ECHO) and the early diastolic velocity of the mitral annulus was measured by tissue Doppler imaging (TDI).

Left ventricular mass was used as a parameter for the assessment of cardiac function. An increase in left ventricular mass leads to ventricular hypertrophy which is a prognostic factor of cardiovascular morbidity and mortality. Left ventricular mass was measured by ECHO, which was calculated as (1.04 * [{left ventricular end diastolic diameter (LVEDD) + septal diastolic thickness + post wall diastolic thickness}^3 - LVEDD^3]) * 0.8 + 0.6. Left ventricular mass was assessed for the two ECHO modes: parasternal long-axis two dimensional (PLAX 2D) mode and parasternal short-axis view motion (PSAX M) mode.

The MLHF is a 21-item questionnaire which used to evaluate QoL in participants suffering from heart failure. The participants were asked to evaluate how their heart condition affected their life during the past month. Each of the 21 items were assessed on a 6-point scale, where 0 = no affect and 5 = very much affected. The MLHF QoL total score was calculated as the sum of the 21 individual QoL questions. The MLHF QoL total score ranged from 0 to 105, where higher scores indicated worse health condition.

The MLHF is a 21-item questionnaire which is used to evaluate QoL in participants suffering from heart failure. The participants were asked to evaluate how their heart condition affected their life during the past month. Each of the 21 items were assessed on a 6-point scale, where 0 = no affect and 5 = very much affected. The MLHF QoL physical score was calculated as the sum of the 8 physical domain QoL questions. The MLHF QoL physical score ranged from 0 to 40, where higher scores indicated worse health condition.

The MLHF is a 21-item questionnaire which is used to evaluate QoL in participants suffering from heart failure. The participants were asked to evaluate how their heart condition affected their life during the past month. Each of the 21 items were assessed on a 6-point scale, where 0 = no affect and 5 = very much affected. The MLHF QoL emotional score was calculated as the sum of the 5 emotional domain QoL questions. The MLHF QoL emotional score ranged from 0 to 25, where higher scores indicated worse health condition.

Participants were classified by NYHA functional class. NYHA class I: participants with cardiac disease but without resulting limitations of physical activity, NYHA class II: participants with cardiac disease resulting in slight limitation of physical activity, NYHA class III: participants with cardiac disease resulting in marked limitation of physical activity, NYHA class IV: participants with cardiac disease resulting in inability to carry on any physical activity without discomfort. Baseline was reported by NYHA functional class and the change from baseline in the functional class was reported as improvement (positive change from baseline), no change and deterioration (negative change from baseline).