The Effect of Successful Heart Transplant Treatment of Heart Failure on Central Sleep Apnea: CSA

The Effect of Successful Heart Transplant Treatment of Heart Failure on Central Sleep Apnea: CSAOf the 13 patients with CSA before transplant, 3 patients had persistent CSA, 4 patients had OSA, and 6 patients had no SDB (AHI, 36.1 ± 10.0 to 12.3 ± 0.9/h, 18.0 ± 4.2 to 11.2 ± 7.4/h, and 31.4 ± 6.5 to 1.3 ± 0.9/h, respectively) on follow-up sleep studies. The characteristics of the CSA changed significantly with transplantation, such that cycle length shortened significantly (65 ± 14 to 31 ± 7 s, p < 0.01) [Table 3, Fig 1], and the venti-lation:apnea length ratio diminished (2.6 ± 0.9 to 0.7 ± 0.3, p < 0.01) [Table 3]. There was a tendency for greater hypocapnia in the posttransplant CSA group compared with the OSA or no-SDB groups (37.5 ± 0.7 mm Hg, 40.4 ± 4.4 mm Hg, and 38.0 ± 0.6 mm Hg, respectively), but this failed to reach statistical significance. The severity of CSA pretransplant did not predict posttransplant apnea status. In the pretransplant no-SDB control group, all patients remained free of SDB after transplantation.

Four patients from the CSA pretransplant group acquired posttransplant OSA, whereas none of the no SDB pretransplant control group acquired SDB after transplant. The percentage of OSA events in the pretransplant CSA group were similar in those who went on to acquire posttransplant CSA, OSA, and no SDB (12 ± 17%, 12 ± 16%, and 12 ± 19%, respectively).
The UNE levels fell significantly following transplantation (48.1 ± 30.9 to 6.5 ± 4.8 nmol/mmol creatinine, p < 0.01) in the CHF group with CSA, and a similar trend was demonstrated in the CHF control group with no SDB (21.1 ± 15.5 to 5.8 ± 4.0 nmol/ mmol creatinine, p = 0.20) [Table 3, Fig 2]. The UNE values were not statistically significantly different between the posttransplant CSA, OSA, and no-SDB groups (10.5 ± 2.1 nmol/mmol creatinine, 7.3 ± 4.8 nmol/mmol creatinine, and 4.7 ± 2.9 nmol/mmol creatinine, respectively). add comment

Posttransplant medications are shown in Table 4 and reveal no significant difference in the medication usage between the CSA, OSA, and no SDB groups. Standard posttransplant medications were prescribed for immunosuppressive, cholesterol-lowering, and antihypertensive actions.
Fig1
Figure 1. Overnight UNE levels in the CSA and control groups, respectively, before and after heart transplant. Creat = creatinine.
Fig2
Figure 2. Top, A: Polysomnography of patient before heart transplantation demonstrating typical CSA with Cheyne-Stokes pattern of respiration during stage 2 non-rapid eye movement sleep. Note the crescendo-decrescendo ventilation interspersed by absence of ventilation associated with an arousal at peak ventilation, a cycle length of approximately 72 s, and a ventilation:apnea length ratio of approximately 2.0. Bottom, B : Polysomnography of same patient 10 months following successful heart transplantation demonstrating CSA with a similar Cheyne-Stokes pattern of respiration to that of top, A, except for the markedly shortened cycle length of approximately 31 s and a ventilation:apnea length ratio of approximately 0.7. EOG = electrooculogram; EMG = electromyogram.

Table 4 —Posttransplant Medications

Medications Control Group (n = 9)

No SDB

CSA Group (n = 13)
CSA (n = 3) OSA (n = 4) No SDB (n = 6)
Cyclosporin A 89 (216) 100 (212) 75 (207) 100 (228)
Azathioprine 77 (90) 66 (87.5) 75 (150) 50 (133)
Sirolimus 22 (2.25) 33 (5) 25(1) 33 (5)
Prednisone 55 (7) 33 (5) 50 (7) 66 (9)
Calcium-channel blockers 55 33 50 50
Statins 100 100 75 83
ACE inhibitors 66 66 50 33
Diuretics 33 33 25 50
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