Eur J Cardiothorac Surg. 2007 Feb 28; 

Brain oxygen and metabolism is dependent on the rate of low-flow cardiopulmonary
bypass following circulatory arrest in newborn piglets.

Pastuszko P, Liu H, Mendoza-Paredes A, Schultz SE, Markowitz SD, Greeley WJ,
Wilson DF, Pastuszko A.

Department of Surgery, The University of Oklahoma, Oklahoma City, OK, United
States.

Objective: To determine the optimum rate of low-flow hypothermic cardiopulmonary
bypass (LF), following circulatory arrest (DHCA) on brain oxygenation (bO(2)),
extracellular dopamine (DA), phosphorylation of select neuroregulatory proteins
responsible for neuronal injury, and survival following ischemic brain injury:
CREB, Erk1/2, Akt, Bcl-2, and Bax. Methods: The piglets were placed on
cardiopulmonary bypass (CPB) and cooled to 18 degrees C. They were then
subjected to 30min of DHCA followed by 1h of LF at 20, 50, or 80ml/(kg/min),
rewarmed, separated from CPB, and maintained for 2h. The bO(2) was measured by
quenching of phosphorescence; DA by microdialysis; phosphorylation of CREB,
ERK1/2, Akt, Bcl-2, and Bax by Western blots. The results are means+/-SD for
seven experiments. Results: Pre-bypass bO(2) was 47.4+/-4.2mmHg and decreased to
1.9+/-0.8mmHg during DHCA. At the end of LF at 20, 50, and 80ml/(kg/min), bO(2)
was 11.8+/-1.6, 26+/-1.8, and 33.9+/-2.6mmHg, respectively. The DA increased
510-fold relative to control (p<0.001) by 15min of LF-20 with maximum increase
occurring at 45min. With LF-50, increase in DA was not statistically significant
and no increase was observed when LF-80 was used. Bcl-2 immunoreactivity
increased after LF-50 and LF-80 (140+/-14.5%, p<0.05 and 202+/-34%, p<0.05,
respectively). Neither flow increased Bax immunoreactivity. The ratio of
Bcl-2/Bax, pCREB, pAkt, pErk increased significantly with increasing the flow
rate of LF. Conclusions: The protective effect of LF following DHCA on brain
metabolism is dependent on the flow rate. Flow-dependent increase in pCREB,
pErk1/2, pAkt, increase in Bcl-2/Bax, and decrease in DA indicated that to
minimize DHCA-dependent neuronal injury, LF flow should be above 50ml/(kg/min).

Anaesth Intensive Care. 2007 Feb;35(1):13-9. 

Trends in intra-aortic balloon counterpulsation: comparison of a 669 record
Australian dataset with the multinational Benchmark Counterpulsation Outcomes
Registry.

Lewis PA, Mullany DV, Townsend S, Johnson J, Wood L, Courtney M, Joseph D,
Walters DL.

The General Intensive Care Unit, The Prince Charles Hospital, Brisbane,
Queensland, Australia.

The aim of this study was to review and describe indications for intraaortic
balloon counterpulsation (IABP) use and identify the impact these have on
outcomes at an Australian cardiothoracic tertiary referral hospital. A secondary
aim was comparison of the Australian practice with a large multinational IABP
data registry. Patient demographics, IABP indication, IABP complication rate and
mortality in 662 patients treated with IABP at The Prince Charles Hospital
(TPCH), Brisbane, between January 1994 and December 2004 inclusive were compared
with The Benchmark Counterpulsation Outcomes Registry. Data were collected
between 1994 and 2000 by retrospective patient record review and prospectively
using the Benchmark database from 2001 to 2004. Statistical analysis was
undertaken using SAS (v8.2) software. The mean age of patients managed with IABP
at TPCH (71.6% male) was 63.4 years (SD 12.4). In-hospital mortality rate was
22% and the complication rate was 10.3%. TPCH indications for IABP were: weaning
from cardiopulmonary bypass (34.2%); cardiogenic shock (24.4%); preoperative
support (13%); catheter laboratory support (10.6%); refractory ventricular
failure (7.3%); ischaemia related to intractable ventricular arrhythmias (4.5%);
unstable refractory angina (4%); mechanical complications due to acute
myocardial infarction (1.2%) and other (0.4%) (0.4% not reported). In comparison
to Benchmark, IABP at TPCH demonstrated a prejudice toward intraoperative use
(34.2% versus 16.6%; P < or = 0.0001) and an aversion to catheter laboratory
support (10.6% versus 19%; P < or = 0.0001). TPCH and Benchmark IABP outcomes
demonstrated comparable mortality (22% versus 20.8%; P = ns) but increased TPCH
complications (10.3% vs. 6.2%; P < or = 0.0001) owing to a 2% difference in
observed insertion site bleeding.

JAMA. 2007 Feb 21;297(7):701-8. 

Cognitive and cardiac outcomes 5 years after off-pump vs on-pump coronary artery
bypass graft surgery.

van Dijk D, Spoor M, Hijman R, Nathoe HM, Borst C, Jansen EW, Grobbee DE, de
Jaegere PP, Kalkman CJ; Octopus Study Group.

Department of Anesthesiology, University Medical Center Utrecht, Utrecht, The
Netherlands. d.vandijk@umcutrecht.nl

CONTEXT: Conventional coronary artery bypass graft surgery with use of
cardiopulmonary bypass (on-pump CABG) is associated with excellent long-term
cardiac outcomes but also with a high incidence of cognitive decline. The effect
of avoiding cardiopulmonary bypass (off-pump CABG) on long-term cognitive and
cardiac outcomes is unknown. OBJECTIVE: To compare the effect of off-pump CABG
and on-pump CABG surgery on long-term cognitive and cardiac outcomes. DESIGN,
SETTING, AND PARTICIPANTS: The Octopus Study, a multicenter randomized
controlled trial conducted in the Netherlands, which enrolled 281 low-risk CABG
patients between 1998 and 2000. Five years after their surgery, surviving
patients were invited for a follow-up assessment. INTERVENTION: Patients were
randomly assigned to receive either off-pump (n = 142) or on-pump (n = 139) CABG
surgery. MAIN OUTCOME MEASURE: The primary measure was cognitive status 5 years
after surgery, which was determined by a psychologist blinded to treatment
allocation who administered 10 standardized validated neuropsychological tests.
Secondary measures were occurrence of cardiovascular events (all-cause
mortality, stroke, myocardial infarction, and coronary reintervention), anginal
status, and quality of life. RESULTS: After 5 years, 130 patients were alive in
each group. Cognitive outcomes could be determined in 123 and 117 patients in
the off-pump and on-pump groups, respectively. When using a standard definition
of cognitive decline (20% decline in performance in 20% of the
neuropsychological test variables), 62 (50.4%) of 123 in the off-pump group and
59 (50.4%) of 117 in the on-pump group had cognitive decline (absolute
difference, 0%; 95% confidence interval [CI], -12.7% to 12.6%; P>.99). When a
more conservative definition of cognitive decline was used, 41 (33.3%) in the
off-pump group and 41 (35.0%) in the on-pump group had cognitive decline
(absolute difference, -1.7%; 95% CI, -13.7% to 10.3%; P = .79). Thirty off-pump
patients (21.1%) and 25 on-pump patients (18.0%) experienced a cardiovascular
event (absolute difference, 3.1%; 95% CI, -6.1% to 12.4%; P = .55). No
differences were observed in anginal status or quality of life. CONCLUSION: In
low-risk patients undergoing CABG surgery, avoiding the use of cardiopulmonary
bypass had no effect on 5-year cognitive or cardiac outcomes. TRIAL
REGISTRATION: isrctn.org Identifier: ISRCTN69438133.

J Cardiovasc Surg (Torino). 2007 Feb;48(1):85-91. 

Minimally invasive aortic root replacement: a bridge too far?

Bakir I, Casselman F, De Geest R, Wellens F, Foubert L, Degrieck I, Van Praet F,
Vermeulen Y, Vanermen H.

Department of Cardiovascular and Thoracic Surgery, OLV Clinic, Aalst, Belgium.

AIM: Minimally invasive aortic valve surgery has been studied widely with
outcomes comparable or better than standard sternotomy. We recently reported on
decreased blood loss, cross clamp time and length of hospital stay when compared
to conventional full sternotomy. We expanded the indication to aortic root
surgery and report here our 8 years experience. METHODS: From December 1997 to
November 2005, 35 patients (mean age 51.3+/-15 years) underwent aortic root
replacement, through a partial upper J-sternotomy. A homograft was implanted in
26 (74.3%) patients; the remainder received a valved (4 bioprosthesis, 5
mechanical) conduit. Mean preoperative euroscore was 7+/-2.7 and mean predicted
mortality was 11.5+/-13.8%. Mean and median follow-up time was 51+/-31 and 66
months, respectively. RESULTS: Mean aortic cross clamp and cardiopulmonary
bypass time were 126+/-25 and 182+/-61 min respectively. Revision for bleeding
was necessary in 1 (2.9%) patient. Mean extubation time was 10.4+/-4.8 hours. No
postoperative strokes occurred. Intensive care unit stay ranged from 1 to 42
days (2.7+/-7.4 days, median 1). There were 3 (8.5%) early deaths (sepsis,
multi-organ failure and low cardiac output) and 2 late non-cardiac deaths.
Hospital morbidity included acute renal failure (n=3), pacemaker implantation
(n=3), and prolonged ventilation (n=3). Eleven (31.4%) patients experienced
atrial fibrillation. No other reoperations were performed. Actuarial survival at
99 months was 74.4% (n=30). CONCLUSIONS: Our results indicate that minimally
invasive aortic root replacement is a challenging but feasible procedure with a
lower observed mortality than predicted mortality. We continue to perform this
procedure in good risk patients.

J Cardiothorac Vasc Anesth. 2007 Feb;21(1):61-7. 

Effects of deep hypothermic circulatory arrest with retrograde cerebral
perfusion on electroencephalographic bispectral index and suppression ratio.

Hayashida M, Sekiyama H, Orii R, Chinzei M, Ogawa M, Arita H, Hanaoka K,
Takamoto S.

Department of Anesthesiology, Graduate School of Medicine, The University of
Tokyo, Tokyo, Japan. hayashida-todai@umin.ac.jp

OBJECTIVE: No systematic study has been conducted to investigate effects of deep
hypothermic circulatory arrest (DHCA) on electroencephalographic bispectral
index (BIS) and suppression ratio (SR). Thus, the effects of DHCA were evaluated
on BIS and SR. DESIGN: A prospective clinical study. SETTING: University
hospital (single institute). PARTICIPANTS: Twenty consecutive patients
undergoing thoracic aortic surgery using DHCA under narcotics-sevoflurane
anesthesia. INTERVENTIONS: BIS and SR were monitored during cardiopulmonary
bypass, simultaneously with nasopharyngeal temperature (NPT). MEASUREMENTS AND
MAIN RESULTS: BIS decreased to 0 with induction of deep hypothermia and rose
again with rewarming, although rates of BIS changes in response to cooling and
rewarming varied widely among patients. Typically, BIS decreased slowly until
NPT reached 26 degrees C during cooling and then it began to decrease rapidly
and reached 0 at 17 degrees C, in inverse proportion to SR, which increased
rapidly with deep hypothermia and reached 100% at 17 degrees C. When SR was 50%
or more, BIS was determined by SR according to the expression: BIS = 50-SR/2.
With rewarming, BIS rose again and returned to precooling baseline levels. Time
to the beginning of the BIS recovery significantly correlated with duration of
DHCA. CONCLUSIONS: With induction of deep hypothermia, BIS decreased in a
biphasic manner to 0 at rates varying among patients. With rewarming, BIS rose
again at rates extremely widely varying among patients. The rate of BIS recovery
was related to duration of DHCA. BIS may be capable of conveniently tracing
suppression and recovery of a part of cerebral electrical activity before,
during, and after DHCA.

J Cardiothorac Vasc Anesth. 2007 Feb;21(1):28-34. 

Effect of polymer coating (poly 2-methoxyethylacrylate) of the oxygenator on
hemostatic markers during cardiopulmonary bypass in children.

Eisses MJ, Geiduschek JM, Jonmarker C, Cohen GA, Chandler WL.

Department of Anesthesiology and Pain Medicine, University of Washington School
of Medicine, Seattle, WA 98105, USA. michael.eisses@seattlechildrens.org

OBJECTIVE: Heparin and other oxygenator coatings have been used in attempts to
reduce hemostatic activation during cardiopulmonary bypass (CPB). This study
evaluated whether an oxygenator coated with poly 2-methoxyethylacrylate (PMEA)
(X-coating; Terumo Corporation, Tokyo, Japan) would cause less activation of
coagulation and fibrinolytic systems during CPB in children than a noncoated
oxygenator. DESIGN: Observational study. SETTING: University-affiliated
children's hospital. PATIENTS: Twenty-six patients, 3 months to 5 years old, who
underwent congenital heart surgery for repair of a ventricular septal defect,
atrial septal defect, or both. INTERVENTIONS: Patients were divided into 2
age-matched groups based on the type of oxygenator used: a noncoated oxygenator
(group NC) versus a PMEA-coated oxygenator (group C). MEASUREMENTS AND MAIN
RESULTS: Blood samples for coagulation and fibrinolytic markers were compared
before, during, and after CPB. Despite increases in thrombin generation markers
(F1.2 and TAT) at certain times during CPB in group C compared to group NC, a
comparison over all times during CPB were not statistically different between
groups. Overall D-dimer concentrations during CPB were elevated in group C
compared to group NC (p = 0.02). Active tPA and active PAI-1 were not different
between groups during or after CPB. Group C had higher platelet counts (181,000
+/- 29,000) during CPB than group NC (155,000 +/- 57,000, p = 0.04) but not
postoperatively. Twelve hours postoperatively, chest tube outputs were 8.8 +/- 3
mL/kg in group C and 19.1 +/- 12 mL/kg in group NC (p = 0.003). The
corresponding outputs 24 hours after surgery were 12.4 +/- 3 mL/kg and 24 +/- 11
mL/kg, respectively (p = 0.005). CONCLUSIONS: Except for a somewhat higher
platelet count during CPB, there was no indication that PMEA coating resulted in
less activation of coagulation and fibrinolytic systems. The lower postoperative
chest tube output observed after CPB with PMEA-coated oxygenators needs to be
studied further.

JAMA. 2007 Feb 7;297(5):471-9. 

Mortality associated with aprotinin during 5 years following coronary artery
bypass graft surgery.

Mangano DT, Miao Y, Vuylsteke A, Tudor IC, Juneja R, Filipescu D, Hoeft A,
Fontes ML, Hillel Z, Ott E, Titov T, Dietzel C, Levin J; Investigators of The
Multicenter Study of Perioperative Ischemia Research Group; Ischemia Research
and Education Foundation.

Ischemia Research and Education Foundation, San Bruno, Calif 94066 , USA.
dtb@iref.org

CONTEXT: Acute safety concerns have been raised recently regarding certain
hemorrhage-sparing medications commonly used in cardiac surgery. However, no
comprehensive data exist regarding their associations with long-term mortality.
OBJECTIVE: To contrast long-term all-cause mortality in patients undergoing
coronary artery bypass graft (CABG) surgery according to use of 2 lysine analog
antifibrinolytics (aminocaproic acid and tranexamic acid), the serine protease
inhibitor aprotinin, or no antibleeding agent. DESIGN, SETTING, AND
PARTICIPANTS: Observational study of mortality conducted between November 11,
1996, and December 7, 2006. Following index hospitalization (4374 patients; 69
medical centers), survival was prospectively assessed at 6 weeks, 6 months, and
annually for 5 years after CABG surgery among 3876 patients enrolled in a
62-center international cohort study. The associations of survival with
hemorrhage-sparing medications were compared using multivariable analyses
including propensity adjustments. MAIN OUTCOME MEASURE: Death (all-cause) over 5
years. RESULTS: Aprotinin treatment (223 deaths among 1072 patients [20.8%
5-year mortality]) was associated with significantly increased mortality
compared with control (128 deaths among 1009 patients [12.7%]; covariate
adjusted hazard ratio for death, 1.48; 95% confidence interval, 1.19-1.85),
whereas neither aminocaproic acid (132 deaths among 834 patients [15.8%];
adjusted hazard ratio for death, 1.03; 95% confidence interval, 0.80-1.33) nor
tranexamic acid (65 deaths among 442 patients [14.7%]; adjusted hazard ratio for
death, 1.07; 95% confidence interval, 0.80-1.45) was associated with increased
mortality. In multivariable logistic regression, either with propensity
adjustment or without, aprotinin was independently predictive of 5-year
mortality (adjusted odds ratio with propensity adjustment, 1.48; 95% confidence
interval, 1.13-1.93; P = .005) among patients with diverse risk profiles, as
well as among those surviving their index hospitalization. Neither aminocaproic
nor tranexamic acid was associated with increased risk of death. CONCLUSIONS:
These findings indicate that in addition to the previously reported acute renal
and vascular safety concerns, aprotinin use is associated with an increased risk
of long-term mortality following CABG surgery. Use of aprotinin among patients
undergoing CABG surgery does not appear prudent because safer and less expensive
alternatives (ie, aminocaproic acid and tranexamic acid) are available.

Eur Surg Res. 2007 Feb 1;39(2):67-74 

Open-Heart Surgery in Patients with Liver Cirrhosis: Indications, Risk Factors,
and Clinical Outcomes.

An Y, Xiao YB, Zhong QJ.

Department of Cardiovascular Surgery, Xin-Qiao Hospital, Third Military Medical
University, Chongqing, China.

Background: Because of recent advances in cardiopulmonary bypass (CPB) surgery,
there are broadened indications to approach patients with a high operative risk.
Meanwhile, there is an increasing number of patients with severe liver
dysfunction subjected to open-heart surgery. This retrospective study was
designed to evaluate the operative indications and clinical outcomes in patients
with liver cirrhosis (LC) undergoing open-heart surgery. In addition,
determinants influencing their prognosis were assessed. Patients and Methods:
Between May 1996 and June 2005, 24 patients with LC underwent CPB open-heart
surgery in our institution. The preoperative severity of the LC was determined
according to the Child-Pugh classification. Their perioperative data were
analyzed. Several perioperative factors were compared by multivariate logistic
regression analysis between survivors and nonsurvivors to determine possible
risk factors contributing to mortality. Results:There were 14 females and 10
males. Their age ranged from 36 to 72 (mean 53 +/- 13) years. Seventeen cases
were classified as having Child-Pugh class A LC, 6 as having Child-Pugh class B,
and 1 as having Child-Pugh class C LC. All patients underwent CPB surgery. The
mean operation time and the cross-clamp time were 160 +/- 53 and 90 +/- 42 min,
respectively. During the first 24 h after the operation, the mean chest tube
output was 1,080 +/- 320 ml. The mean duration of mechanical ventilation was 32
+/- 22 h, and the mean intensive care unit stay was 11 +/- 8 days. Sixty-six
percent of the patients experienced significant morbidity. Fifty-three percent
of the patients with Child-Pugh class A LC and 100% of those with Child-Pugh
class B and C LC suffered postoperative complications. The overall mortality
rate was 25%. The postoperative mortality rates of the patients with Child-Pugh
class A, B, and C LC were 6, 67, and 100%, respectively. Preoperative serum
total bilirubin and cholinesterase levels and EuroSCORE (European System for
Cardiac Operative Risk Evaluation) values along with CPB time were identified as
the important predictors to differentiate between survivors and nonsurvivors by
multivariate logistic regression analysis. Conclusions: The Child-Pugh class is
associated with hepatic decompensation and mortality after open-heart CPB
surgery in patients with LC. Such surgery can be performed safely in patients
with a Child-Pugh class A LC. But cardiac interventions using CPB in patients
with more advanced LC are associated with high mortality and morbidity rates.
The preoperative total plasma bilirubin and cholinesterase concentrations as
well as the EuroSCORE along with the CPB time are identified as statistically
significant predictors of mortality after open-heart surgery in patients with
LC. Our findings indicate that patients with chronic liver disease scheduled for
open-heart surgery should be carefully evaluated before the operation and that
the CPB duration should be as short as possible. Copyright (c) 2007 S. Karger
AG, Basel.

Yakugaku Zasshi. 2007 Feb;127(2):375-83. 

Effects of low-dose milrinone on weaning from cardiopulmonary bypass and after
in patients with mitral stenosis and pulmonary hypertension.

Oztekin I, Yazici S, Oztekin DS, Goksel O, Issever H, Canik S.

Anesthesiology Department, Siyami Ersek Thoracic and Cardiovascular Surgery
Hospital, Haydarpasa, Istanbul, Turkey. dnzoztekin@hotmail.com

The phosphodiesterase inhibitor milrinone is usually preferred in patients with
pulmonary hypertension and myocardial dysfunction after cardiopulmonary bypass.
We investigated the effects of low-dose milrinone on pulmonary hypertension in
the immediate pre- and postoperative period. Forty-seven patients were
randomized to the control and milrinone groups. All patients had mean pulmonary
artery pressure greater than 30 mmHg and pulmonary capillary wedge pressure
greater than 20 mmHg and were candidates for mitral valve replacement for
rheumatic mitral stenosis. Twenty-four patients received a loading dose of
milrinone 25 microg/kg(-1) during weaning from cardiopulmonary bypass, followed
by a maintenance dose of 0.25 microg/kg(-1)/min(-1) to the end of the surgery.
Cardiac output and other hemodynamic variables were noted at induction, weaning
from bypass, and postoperative 1 h. Pulmonary artery pressure, capillary wedge
pressure, and central venous pressure were significantly lower in the milrinone
group during weaning after cardiopulmonary bypass, while other variables were
roughly similar. However, patients in the control group required higher doses of
vasodilators, inotropes, and antiarrhythmic agents. Mean arterial pressure in
the milrinone group was significantly lower at 1 h postoperatively than in the
control group; however, the patients did not need many more vasopressors. Fluid
restriction and diuretic agent use were more significant in the control group.
Systemic arterial hypotension and vasopressor requirements with milrinone use at
inotropic doses were not observed at the doses used for the study. A total of
21.7% of the patients in the control group required vasopressors in the
perioperative period. Both groups demonstrated similar hematologic variables
except that the hemoglobin level in the control group was significantly lower
during postoperative days 1 and 7. Low-dose milrinone for a short-term during
weaning from cardiopulmonary bypass may be used in patients with mitral stenosis
and pulmonary hypertension for its effects on pulmonary artery pressures, less
inotropic and vasopressor requirements, and fluid balance.

Ann Thorac Surg. 2007 Feb;83(2):572-7. 

Bivalirudin during cardiopulmonary bypass in patients with previous or acute
heparin-induced thrombocytopenia and heparin antibodies: results of the
CHOOSE-ON trial.

Koster A, Dyke CM, Aldea G, Smedira NG, McCarthy HL 2nd, Aronson S, Hetzer R,
Avery E, Spiess B, Lincoff AM.

Department of Anesthesia, Deutsches Herzzentrum Berlin, Germany. koster@dhzb.de

BACKGROUND: The coronary artery bypass grafting (CABG) heparin-induced
thrombocytopenia thrombosis syndrome (HITTS) on- and off-pump safety and
efficacy (CHOOSE-ON) trial was designed as a safety and efficacy trial of
bivalirudin for use in anticoagulation during cardiopulmonary bypass (CPB) in
patients with confirmed or suspected HIT and (or) antiplatelet factor 4/heparin
(anti-PF4/H) antibodies. METHODS: In an open-label, multicenter trial, 50
patients were enrolled prospectively. The primary study endpoint was in-hospital
acute procedural success, defined as the absence of death, Q-wave myocardial
infarction (MI), repeat operation for coronary revascularization, and stroke at
day seven after surgery or hospital discharge, whichever occurred first. The
secondary study endpoints were procedural success, defined as the absence of
death, Q-wave MI, repeat operation for coronary revascularization, and stroke,
at 30 days and 12 weeks after surgery. Perioperative blood loss, transfusions,
and the incidence of major bleeding events were also captured. RESULTS: There
were 49 patients treated with bivalirudin of which 43 had acute HIT and
thrombosis syndrome (HITTS) with antibodies at time of surgery. Procedural
success in-hospital or at 7 days was achieved in 46 (94%) patients. At day 30
procedural success was achieved in 42 (86%) patients, and after 12 weeks in 40
(82%) patients. Mean intraoperative blood loss was 575 +/- 524 mL, and mean
24-hour postoperative blood loss was 998 +/- 595 mL. Forty-one (84%) patients
received transfusions before day 7 or discharge with a mean of 5.6 +/- 3.8 units
of red blood cells, 8.6 +/- 7.2 units of platelets, and 6.0 +/- 4.7 units of
fresh frozen plasma. No differences in outcome among bivalirudin-treated
patients were observed between those in the overall group and those with
moderately impaired renal function (n = 10). CONCLUSIONS: The current
investigation expands the experience of safe and effective anticoagulation with
bivalirudin during CPB to patients with confirmed or suspected HIT and
anti-PF4/H antibodies, including in the setting of impaired renal function.