Coronary Sinus Narrowing Improves Right Ventricular Function

Central Illustration

Right ventricular (RV) function affects outcome in coronary artery disease (CAD) patients. 1 Elevating coronary sinus (CS) pressure with the use of coronary Reducer device (Neovasc) was shown to improve subendocardial blood flow in the ischemic heart, alleviate ischemia and angina, and improve left ventricular (LV) function. 2,3 We tested whether in patients with refractory angina and ischemia, who are treated with Reducer implantation, the increased CS pressure will also improve RV performance.
We conducted a single-center, single-arm, openlabeled prospective study, enrolling consecutive patients with obstructive CAD and refractory angina despite optimal medical therapy, who were not candidates for revascularization procedures. All participants had objective evidence of reversible myocardial ischemia in technetium sestamibi scan, LV ejection fraction (LVEF) $35%, and no significant valvular disease. Primary pulmonary hypertension was excluded when appropriate.

Improvement in RV function indices after Reducer
implantation was shown in the entire cohort but reached statistical significance in the subgroup of patients with baseline RV dysfunction (S' 8 AE 1.2 cm/s to 9.5 AE 1.5 cm/s; P ¼ 0.01; RV FAC 34.1 AE 5.4% to 36.7 AE 5.1%; P ¼ 0.033; MPI 0.56 AE 0.07 to 0.49 AE 0.05; P ¼ 0.036, and TAPSE from 15.8 AE 3.2 cm to 16.2 AE 2.9 cm; P ¼ 0.001, before and after Reducer implantation, respectively) ( Figure 1). The improvement in RV function was not associated with either LV systolic or diastolic function change (P for interaction ¼ 0.6).
However, lateral LV wall ischemia was associated with an improvement in several RV function indices (P for interaction ¼ RV FAC 0.024, S' 0.011 cm/s, and MPI 0.008, respectively).
Though physiological differences in afterload, wall stress, and myocardial perfusion allow the RV to better recover from ischemic injury, 5,6 its function  equipped with: 1) an actigraph that can detect physical movements in 3 directions using an accelerometer; 2) a thermometer; and 3) a barometer. 2 In the present study, actisensitivity is defined as the slope of the regression line that is calculated from 24-h ambulatory systolic BP (SBP) with the log-transformed value corresponding to the 5-minute average of physical activity just before each BP measurement ( Figure 1). 1,2 In the present study, we prospectively assessed the changes in actisensitivity and ambulatory blood pressure (ABP) parameters between patients with and without improved cardiac function during the treatment of HF.
We assessed multisensor-ABPM data in 20 patients with diagnosed HF (mean age, 63.3 AE 14.1 years; male: 65%; ischemic heart disease: 15%; atrial fibrillation: 25%) just after initial or adjusted treatments, and reassessed the multisensor-ABPM data at follow-up from 6-12 months after tailored treatment. Second, we divided these patients into an improved (n ¼ 11 patients) and a not-improved (n ¼ 9) cardiac-function group; an increase in echocardiographic left ventricular ejection fraction (LVEF) of $10% as determined using the biplane method of disks was used as the cutoff. 3 We then compared the changes in actisensitivity and ABP parameters between the 2 groups.
Multisensor-ABPM was measured automatically at 30-min intervals for 24 hours using an oscillometric method, and the daytime and nighttime were based on a diary. These changes were not observed in the notimproved group. Parameters of ABP variability-ie, SD, coefficient of variation, and average real variability of SBP over 24 hours, daytime or nighttimewere not significantly different between baseline and follow-up in either group. Additionally, physical activity (G) did not change between baseline and follow-up in either group. However, the actisensitivity value tended to increase from baseline to follow-up in the improved group (1.0 AE 3.5 vs 4.5 AE 3.5; P ¼ 0.065), but not in the not-improved group (3.2 AE 5.4 vs 2.0 AE 6.3; P ¼ 0.479). The degree of changes in actisensitivity from baseline to follow-up tended to be higher in the improved group than the not-improved group (3.5 AE 5.6 vs À1.2 AE 4.8; P ¼ 0.059). Moreover, in the overall patient group, the change of actisensitivity from baseline to follow-up was significantly related to the changes of LVEF (r ¼ 0.553; P ¼ 0.011) (Figure 1).