Systemic to pulmonary collateral blood flow influences early outcomes following the total cavopulmonary connection

BACKGROUND

Systemic to pulmonary collaterals (SPCs) represent an additional and unpredictable source of pulmonary blood flow in patients with single ventricle physiology following bidirectional superior cavopulmonary connection (BCPC). Understanding their influence on patient outcomes has been hampered by uncertainty about the optimal method of quantifying SPC flow.

OBJECTIVE

To quantify SPC flow by cardiac magnetic resonance (CMR) prior to total cavopulmonary connection (TCPC) in order to identify preoperative risk factors and determine influence on postoperative outcomes.

DESIGN

Single centre prospective cohort study.

SETTING

Tertiary referral centre.

PATIENTS

65 patients with single ventricle physiology undergoing CMR for preoperative assessment of TCPC completion underwent quantification of SPC flow. Clinical outcomes of 41 patients in whom TCPC was completed were obtained.

MAIN OUTCOME MEASURES

Early post-TCPC clinical outcomes associated with SPC flow were assessed, including postoperative chest drainage volume, postoperative chest drainage duration and length of intensive care and hospital stays. Additionally preoperative covariates associated with SPC flow were assessed including age at BCPC and CMR, SpO(2) at BCPC and CMR, ventricle type, pulmonary artery (PA) cross-sectional area and PA pulsatility. Different methods of CMR SPC flow quantification were compared.

RESULTS

Higher SPC flow was associated with increased postoperative chest drain volume (r=0.51, p=0.001), chest drain duration (r=0.43, p=0.005), and intensive care unit (r=0.32, p=0.04) and log-transformed hospital stays (r=0.31, p=0.048). The effect of SPC flow on outcome was independent of fenestration, ventricle type and function. Preoperative covariates associated with SPC flow included age at BCPC (β=-0.34, p=0.008), SpO(2) at time of CMR (β=0.34, p=0.004) and branch PA cross-sectional area (β=-0.26, p=0.036), model R(2)=0.34. Moreover, patients with pulsatile pulmonary blood flow had lower SPC flow than those without (0.8 vs 1.3 l/min/m(2) p=0.012). SPC flow calculated by the difference between pulmonary venous return and pulmonary artery flow (l/min/m(2)) showed greatest association with preoperative covariates and strongest correlation with postoperative outcomes compared with other methods of quantification.

CONCLUSIONS

CMR can provide an effective measurement of SPC flow prior to TCPC. Young age at BCPC, high preoperative oxygen saturation and smaller PAs are associated with increased SPC flow, which may promote increased postoperative pleural drainage and lengthen recovery.

Calcium, Calcium Regulatory Hormones, and Calcimimetics: Impact on Cardiovascular Mortality

Calcemia is a risk factor for cardiovascular (CV) events in dialyzed patients. The relation between serum calcium and cardiovascular events is continuous and linear. Calcium plays a potent role in the genesis of cardiovascular dysfunction, particularly by promoting vascular calcification. Parathyroid hormone (PTH) also is associated with increased CV risk in both primary and secondary hyperparathyroidism. There is a nonlinear relationship between PTH and CV risk; both high and low PTH concentrations increase CV risk. The CV risk profile (BP, dyslipidemia) is strikingly ameliorated by the administration of calcimimetics. Apart from lowering PTH, whether calcimimetics have intrinsic effects on CV risk profile is unknown.

Acute Blood Pressure Effects and Chronic Hypotensive Action of Calcimimetics in Uremic Rats

A previous study in subtotally nephrectomized (SNX) rats suggested beneficial effects of the calcimimetic R-568 beyond the control of mineral metabolism. This study analyzed potential blood pressure (BP)-lowering effects of R-568. Male Sprague-Dawley rats received two-stage subtotal nephrectomy or sham operation. Telemetry devices were inserted into the abdominal aorta, and BP was measured every 5 min. R-568 (20 mg/kg per d) or solvent was infused for 4 wk followed by once-daily subcutaneous injections for 2 wk. Total body sodium was measured by neutron activation analysis. The uremia-induced increase of mean arterial pressure from baseline to day 42 in SNX solvent rats (103+/-5 to 128+/-14 mmHg, P=0.006) was attenuated by R-568 (104+/-5 to 111+/-8 mmHg; P<0.0001 for difference of slopes). The circadian rhythm was abrogated in SNX rats and not restored by R-568. In sham-operated rats, R-568 had only a minor transient antihypertensive effect. R-568 injection induced a transient rise of mean arterial pressure by 23+/-4 and 26+/-10 mmHg in sham and SNX rats but only by 9+/-3 and 10+/-5 mmHg in solvent-treated rats (P<0.01 versus baseline and solvent versus R-568). Plasma angiotensin-converting enzyme activity and aldosterone levels were similar; food intake and physical activity did not differ throughout the study. In healthy rats, total body sodium was higher after 14 d of R-568 compared with solvent infusion (37.1+/-4 versus 32.5+/-1.4 mmol/kg; P=0.01). The calcimimetic R-568 causes an initial BP increase in sham-operated and uremic rats, which in uremic rats is followed by a marked and sustained antihypertensive effect.

Nodal peripheral T-cell lymphomas and, in particular, their lymphoepithelioid (Lennert?s) variant are often derived from CD8+ cytotoxic T-cells

Nodal peripheral T-cell lymphomas are not well understood, and most of them are classified in the "not otherwise specified group" (PTCL-NOS). Data on their normal cellular derivation are ambiguous. Most peripheral T-cell lymphomas are composed of tumor cells and a (sometimes dominant) reactive background, which also includes resting and activated T-lymphocytes. We defined the phenotype of the tumor cells in 101 PTCL-NOS based on their cytological atypia and using immunohistochemical double stains on paraffin sections with CD4/Ki67 and CD8/Ki67. The results were correlated to clinical presentation and outcome. Lineage could be defined in 98 cases (97%). Tumor cells were CD4(+) in 43 cases and CD8(+) in 38. These presented at a younger age but a higher clinical stage compared with the CD4(+) lymphomas. In 15 cases, the atypical cells were CD4(-)CD8(-); two cases were CD4(+)CD8(+). Of 17 lymphoepithelioid (Lennert's) lymphomas, 15 expressed CD8, one each was CD4(+) and CD4(-)CD8(-).

Angioimmunoblastic T cell lymphoma is derived from mature T-helper cells with varying expression and loss of detectable CD4

Angioimmunoblastic T cell lymphoma (AILT) is a rare lymphoma that is regarded as a clinicopathologic entity but shows considerable histomorphologic diversity, variable immunophenotypes and inconsistent T cell receptor (TCR) gene rearrangement. One hundred four paraffin blocks of AILT were investigated defining tumor cell lineage by triple immunostains with a confocal laser scanning microscope and correlating morphology, immunophenotype and TCRgamma gene rearrangement to clinical outcome. Ninety-nine cases were CD4(+), some of them showing a mixture of CD4(+) and CD4(-) tumor cells. The remaining 5 specimens were CD3(+)/CD4(-)/CD8(-). A considerable number of T cells of different subtypes could always be found, but even in 13 cases predominated by CD8(+) cells, proliferation could be attributed to atypical CD4(+) cells. TCRgamma gene rearrangement was monoclonal in 48 cases (69%) among 70 tested. In 29 of these semi-quantitative gene scan analysis resulted in a median proportion of monoclonal peak of 35% of PCR-products. Clinical outcome was identical grouping patients by clonality of TCRgamma, absence or presence of clear cell clusters and international prognostic index. We conclude that AILT is mainly derived from CD2(+)CD3(+)CD4(+)CD5(+)CD7(-) mature T-helper cells with varying expression and partial loss of detectable CD4. A significant number of non-neoplastic T cells (resting CD4(+) T cells and activated small or medium-sized CD8(+) lymphocytes) may coexist with a minor neoplastic T cell population. Clinicopathologic correlation suggests AILT to be a well defined homogeneous entity with poor prognosis. Currently no prognostic factors can be derived.