Elevated immune monitoring early after cardiac transplantation is associated with increased plaque progression by intravascular ultrasound

Angiogenesis on coronary angiography is a marker for accelerated cardiac allograft vasculopathy as assessed by intravascular ultrasound

BACKGROUND

Errant neovascularization and coronary artery fistulae (CAF) are frequently observed after cardiac transplantation. The relationship between angiographic neovascularization/CAF and coronary plaque progression is unknown.

METHODS

Angiography and intravascular ultrasound were routinely performed at 4-6 weeks and 1-year post-transplant. Pts were divided into three groups: no angiographic angiogenesis (Group 1), neovascularization only (Group 2), and CAF (Group 3). First-year changes in maximal intimal thickness (MIT), maximal intimal area (MIA), and percent atheroma volume (PAV) were compared between groups.

RESULTS

The 106 pts were included, 40/106 in Group 1, 42/106 in Group 2, and 24/106 in Group 3. Respectively, first-year ΔMIT was 0.14 ± 0.13 mm, 0.32 ± 0.26 mm, and 0.50 ± 0.34 mm, P < .001. ΔMIA was 0.6 ± 0.6 mm² , 1.7 ± 1.8 mm² , and 3.0 ± 2.6 mm² , P < .001. ΔPAV was 2.3 ± 2.5%, 6.0 ± 5.1%, and 9.6 ± 9.0%, P < .001. Rapid plaque progression occurred in 1/40 (2.5%) pts in Group 1, 12/42 (28.6%) in Group 2, and 12/24 (50%) in Group 3, P < .001. Multivariate analysis identified both antithymocyte globulin and presence of CAF as independently associated with rapid plaque progression: OR 0.29 (P = .038) and 4.04 (P = .014).

CONCLUSION

Neovascularization and CAF are commonly present on surveillance angiography after cardiac transplantation and may signify amplified angiogenesis. Their presence is associated with accelerated coronary plaque progression by IVUS.

Induction Therapy With Antithymocyte Globulin in Patients Undergoing Cardiac Transplantation Is Associated With Decreased Coronary Plaque Progression as Assessed by Intravascular Ultrasound

BACKGROUND

Antithymocyte globulin (ATG) is used as induction therapy after cardiac transplant for enhancing immunosuppression and delaying the initiation of nephrotoxic drugs. It is unknown if ATG induction is associated with decreased coronary plaque progression by intravascular ultrasound (IVUS).

METHODS AND RESULTS

Patients transplanted between March 2010 and December 2012 with baseline and 1-year IVUS were included. All patients transplanted were included in a secondary analysis. Change in plaque progression was measured in a blinded fashion on matched coronary segments and contrasted between patients induced with ATG and those who were not. One hundred and three patients were included in IVUS arms. Mean age at transplant was 55.8 ± 12.6 years, and 33.0% were female. Patients induced with ATG were more sensitized (54.3% versus 14.3%). Plaque progression was attenuated in patients who received ATG by changes in maximal intimal area (1.0 ± 1.2 versus 2.3 ± 2.6 mm(2); P = 0.001), maximal percent stenosis (6.3 ± 7.9 versus 12.8 ± 12.3%; = 0.003), maximal intimal thickness (0.2 ± 0.2 versus 0.3 ± 0.3 mm; P = 0.035), and plaque volume (0.5 ± 0.7 versus 1.0 ± 1.3 mm(3)/mm; P = 0.016). Rapid plaque progression by maximal percent stenosis (≥ 20%) occurred less frequently in the ATG arm (4.3% versus 26.3; P = 0.003). Survival (P = 0.242) and any treated rejection (P = 0.166) were not statistically different between groups. Patients receiving ATG had a higher rate of first-year infection (P = 0.003), perhaps related to increased intravenous antibiotic use immediately postoperatively, and a trend toward more biopsy-proven rejection (P = 0.073).

CONCLUSIONS

Induction therapy with ATG is associated with reduced first-year coronary plaque progression as assessed by IVUS, despite an increased prevalence of sensitized patients with a trend toward more rejection.

Elevated immune monitoring as measured by increased adenosine triphosphate production in activated lymphocytes is associated with accelerated development of cardiac allograft vasculopathy after cardiac transplantation

BACKGROUND

Elevated immune monitoring (IM), as measured by adenosine triphosphate (ATP) release from activated lymphocytes, has been suggested to represent an under-immunosuppressed state. Its association with the development of angiographic cardiac allograft vasculopathy (CAV) is unknown.

METHODS

Patients transplanted between January 2007 and December 2011 with annual angiograms and at least 1 IM assay were included in the analysis. Peak IM scores were determined for each patient. Patients with peak IM in the highest quartile (Group 2) were compared with those with scores in the lower quartiles (Group 1). Mild disease was scored as Grade 1 (CAV1) and moderate or severe disease was scored as Grades 2 or 3 (CAV2/3).

RESULTS

Two hundred forty patients were included. The mean age at transplant was 54.2 ± 12.1 years. Time to peak IM assay was 105.9 ± 44.1 days and average number of assays obtained per patient was 3.1 ± 1.8. Patients in the highest quartile (Group 2) had peak IM ≥446 ng ATP/ml. Mean clinical follow-up was 4.6 ± 1.7 years. CAV1 was observed in 86 of 180 (47.8%) patients in Group 1 and 39 of 60 (65.0%) in Group 2. Freedom from CAV1 was significantly lower in patients in Group 2 (log rank, p = 0.012). CAV2/3 occurred in 7 of 180 (3.7%) patients in Group 1 and 9 of 60 (15.0%) patients in Group 2. Freedom from CAV2/3 was significantly lower in patients in Group 2 (p = 0.003). In multivariate analysis elevated peak IM assay was still found to be associated with angiographic CAV (hazard ratio 1.647, confidence interval 1.020 to 2.661, p = 0.041).

CONCLUSION

Elevated peak IM, as measured by increased ATP production, in activated lymphocytes is associated with decreased freedom from angiographic CAV.