Trial Outcomes & Findings for Evaluating the Presence of Blood Clots in People With Heparin-Induced Thrombocytopenia (HIT) (The HOT Study) (NCT NCT00594685)

Results Overview

The percentage of participants with asymptomatic thrombosis at the time isolated HIT is diagnosed as determined by four-limb ultrasound.

Recruitment status

TERMINATED

Target enrollment

10 participants

Primary outcome timeframe

Measured at Day 1

Results posted on

2013-03-13

Participant Flow

Participant milestones

Participant milestones
Measure	Isolated HIT Hospitalized patients with isolated Heparin-Induced Thrombocytopenia (HIT), diagnosed by a fall in platelet count and a positive Platelet Factor 4 (PF4)-heparin Enzyme-Linked ImmunoSorbent Assay (ELISA) test
Overall Study STARTED	10
Overall Study COMPLETED	10
Overall Study NOT COMPLETED	0

Reasons for withdrawal

Withdrawal data not reported

Baseline Characteristics

Evaluating the Presence of Blood Clots in People With Heparin-Induced Thrombocytopenia (HIT) (The HOT Study)

Baseline characteristics by cohort

Baseline characteristics by cohort
Measure	Isolated HIT n=10 Participants Hospitalized patients with isolated Heparin-Induced Thrombocytopenia (HIT), diagnosed by a fall in platelet count and a positive Platelet Factor 4 (PF4)-heparin Enzyme-Linked ImmunoSorbent Assay (ELISA) test
Age, Categorical <=18 years	0 Participants n=5 Participants
Age, Categorical Between 18 and 65 years	9 Participants n=5 Participants
Age, Categorical >=65 years	1 Participants n=5 Participants
Age Continuous	54.5 years STANDARD_DEVIATION 13.9 • n=5 Participants
Sex: Female, Male Female	3 Participants n=5 Participants
Sex: Female, Male Male	7 Participants n=5 Participants
Region of Enrollment United States	10 participants n=5 Participants

PRIMARY outcome

Timeframe: Measured at Day 1

The percentage of participants with asymptomatic thrombosis at the time isolated HIT is diagnosed as determined by four-limb ultrasound.

Outcome measures

Outcome measures
Measure	Isolated HIT n=10 Participants Hospitalized patients with isolated Heparin-Induced Thrombocytopenia (HIT), diagnosed by a fall in platelet count and a positive Platelet Factor 4 (PF4)-heparin Enzyme-Linked ImmunoSorbent Assay (ELISA) test
The Percentage of Participants With Asymptomatic Thrombosis at the Time Isolated Heparin-Induced Thrombocytopenia (HIT) is Diagnosed, Determined by Four-limb Ultrasound	20 Percentage of participants Interval 3.0 to 56.0

SECONDARY outcome

Timeframe: Measured at Day 35 (+/- 7days)

Population: Four subjects had missing data for this endpoint (no ultrasound performed on end-of-study date) and are not included in this analysis.

The percentage of participants with asymptomatic thrombosis 4 weeks after the diagnosis of isolated HIT, determined by four-limb ultrasound, and 95% exact binomial confidence interval.

Outcome measures

Outcome measures
Measure	Isolated HIT n=6 Participants Hospitalized patients with isolated Heparin-Induced Thrombocytopenia (HIT), diagnosed by a fall in platelet count and a positive Platelet Factor 4 (PF4)-heparin Enzyme-Linked ImmunoSorbent Assay (ELISA) test
The Percentage of Participants With Asymptomatic Thrombosis 4 Weeks After the Diagnosis of Isolated HIT, Determined by Four-limb Ultrasound	19 Percentage of participants Interval 0.0 to 64.0

SECONDARY outcome

Timeframe: Measured within 35 days (+/- 7) after the diagnosis of isolated HIT

Population: Two subjects did not have information on whether the event was symptomatic or asymptomatic. These two subjects were censored in the analysis.

There were two versions of the data collection form used in this study, and only the revised version collected information on whether the event was symptomatic.

Outcome measures

Outcome measures
Measure	Isolated HIT n=10 Participants Hospitalized patients with isolated Heparin-Induced Thrombocytopenia (HIT), diagnosed by a fall in platelet count and a positive Platelet Factor 4 (PF4)-heparin Enzyme-Linked ImmunoSorbent Assay (ELISA) test
The Number of Participants With Symptomatic Venous or Arterial Thromboembolism in the Month Following the Diagnosis of Isolated HIT	0 Participants

SECONDARY outcome

Timeframe: Measured within 35 days (+/- 7) after the diagnosis of isolated HIT

Population: Two subjects did not have information on whether the event was incidental. These subjects were censored in the analysis.

There were two versions of the data collection form used in this study, and only the revised form contained information on whether the event was incidental.

Outcome measures

Outcome measures
Measure	Isolated HIT n=10 Participants Hospitalized patients with isolated Heparin-Induced Thrombocytopenia (HIT), diagnosed by a fall in platelet count and a positive Platelet Factor 4 (PF4)-heparin Enzyme-Linked ImmunoSorbent Assay (ELISA) test
The Number of Participants With Incidental Arterial and Venous Thromboembolism (i.e., a Clot Diagnosed by Radiographic Tests Done for Reasons Other Than to Diagnose or Rule Out a Thromboembolic Event)	0 Participants

SECONDARY outcome

Timeframe: Measured within 35 days (+/- 7) after the diagnosis of isolated HIT

The time to first bleeding event was analyzed using survival analysis.

Outcome measures

Outcome measures
Measure	Isolated HIT n=10 Participants Hospitalized patients with isolated Heparin-Induced Thrombocytopenia (HIT), diagnosed by a fall in platelet count and a positive Platelet Factor 4 (PF4)-heparin Enzyme-Linked ImmunoSorbent Assay (ELISA) test
The Time to First Bleeding Event With Current Therapies for Isolated HIT	10.1 Days Standard Error 2.2

SECONDARY outcome

Timeframe: Measured within 35 days (+/- 7) after the diagnosis of isolated HIT

Population: One subject was censored at the time that the study was terminated.

The time until death from all causes, in days, was determined using survival analysis.

Outcome measures

Outcome measures
Measure	Isolated HIT n=10 Participants Hospitalized patients with isolated Heparin-Induced Thrombocytopenia (HIT), diagnosed by a fall in platelet count and a positive Platelet Factor 4 (PF4)-heparin Enzyme-Linked ImmunoSorbent Assay (ELISA) test
Time Until Death From All Causes	12.2 Days Standard Error 1.1

SECONDARY outcome

Timeframe: Measured within 35 days (+/- 7) after the diagnosis of isolated HIT

Population: One subject's nadir platelet count was \> 100K, so that subject is not included in the analysis.

The time to platelet recovery was defined as the time from the nadir platelet count observed in the five days after the positive HIT test was sent to observing a platelet count of 100K or greater. Survival analysis was used.

Outcome measures

Outcome measures
Measure	Isolated HIT n=9 Participants Hospitalized patients with isolated Heparin-Induced Thrombocytopenia (HIT), diagnosed by a fall in platelet count and a positive Platelet Factor 4 (PF4)-heparin Enzyme-Linked ImmunoSorbent Assay (ELISA) test
Time to Platelet Count Recovery	2.9 Days Standard Error 1.0

SECONDARY outcome

Timeframe: Measured within 35 days (+/- 7) after the diagnosis of isolated HIT

Per the protocol, descriptive statistics on the types and durations of therapeutic approaches used will be presented.

Outcome measures

Outcome measures
Measure	Isolated HIT n=10 Participants Hospitalized patients with isolated Heparin-Induced Thrombocytopenia (HIT), diagnosed by a fall in platelet count and a positive Platelet Factor 4 (PF4)-heparin Enzyme-Linked ImmunoSorbent Assay (ELISA) test
Number of Days That Medications Were Given to Participants at Participating Institutions Alteplase (Activase) - 1 subject	11 Days medication was given Interval 11.0 to 11.0
Number of Days That Medications Were Given to Participants at Participating Institutions Argatroban - 4 subjects	3.5 Days medication was given Interval 3.0 to 4.0
Number of Days That Medications Were Given to Participants at Participating Institutions Aspirin - 4 subjects	36.5 Days medication was given Interval 11.0 to 43.0
Number of Days That Medications Were Given to Participants at Participating Institutions Clopidogrel (Plavix) - 2 subjects	20.5 Days medication was given Interval 4.0 to 37.0
Number of Days That Medications Were Given to Participants at Participating Institutions Fondaparinux (Arixtra) - 3 subjects	10 Days medication was given Interval 6.0 to 11.0
Number of Days That Medications Were Given to Participants at Participating Institutions Ibuprofen (Motrin, Advil) - 1 subject	5 Days medication was given Interval 5.0 to 5.0
Number of Days That Medications Were Given to Participants at Participating Institutions Unfractionated Heparin - 3 subjects	14 Days medication was given Interval 2.0 to 18.0
Number of Days That Medications Were Given to Participants at Participating Institutions Warfarin (Coumadin) - 5 subjects	20 Days medication was given Interval 1.0 to 40.0

SECONDARY outcome

Timeframe: Measured upon hospital discharge

Population: Two subjects were known to be readmitted to the hospital after initially being discharged.

The length of time between the date of HIT diagnosis and first hospital discharge was calculated. Subjects were censored at death. Survival analysis was used.

Outcome measures

Outcome measures
Measure	Isolated HIT n=10 Participants Hospitalized patients with isolated Heparin-Induced Thrombocytopenia (HIT), diagnosed by a fall in platelet count and a positive Platelet Factor 4 (PF4)-heparin Enzyme-Linked ImmunoSorbent Assay (ELISA) test
Length of Hospital Stay	10.4 Days Standard Error 1.3

SECONDARY outcome

Timeframe: Measured upon hospital discharge

Population: Two subjects were known to be readmitted to the hospital after initially being discharged.

The length of time between the date of HIT diagnosis and first hospital discharge was calculated. Subjects were not censored at death. Survival analysis was used.

Outcome measures

Outcome measures
Measure	Isolated HIT n=10 Participants Hospitalized patients with isolated Heparin-Induced Thrombocytopenia (HIT), diagnosed by a fall in platelet count and a positive Platelet Factor 4 (PF4)-heparin Enzyme-Linked ImmunoSorbent Assay (ELISA) test
Length of Hospital Stay (With Deaths Not Censored)	10.1 Days Standard Error 1.4

SECONDARY outcome

Timeframe: Measured at Day 1

Population: Analysis not performed since central laboratory tests were not done.

Analysis not performed since central laboratory tests were not done.

Outcome measures

Outcome data not reported

SECONDARY outcome

Timeframe: Measured at Day 1 and within 35 days (+/- 7) after the diagnosis of isolated HIT

Population: Analysis not performed since central laboratory tests were not done.

Analysis not performed since central laboratory tests were not done.

Outcome measures

Outcome data not reported

SECONDARY outcome

Timeframe: Measured at Day 1 and within 35 days (+/- 7) after the diagnosis of isolated HIT

Population: Analysis not performed since central laboratory tests were not done.

Analysis not performed since central laboratory tests were not done.

Outcome measures

Outcome data not reported

POST_HOC outcome

Timeframe: Measured within 35 days (+/- 7) after the diagnosis of isolated HIT

Since two versions of the data collection form were used in this study, and only the revised version contained information on whether the event was asymptomatic or symptomatic, a post-hoc analysis was performed which included all thromboses, whether symptomatic, asymptomatic, or of unknown type. Survival analysis was used.

Outcome measures

Outcome measures
Measure	Isolated HIT n=10 Participants Hospitalized patients with isolated Heparin-Induced Thrombocytopenia (HIT), diagnosed by a fall in platelet count and a positive Platelet Factor 4 (PF4)-heparin Enzyme-Linked ImmunoSorbent Assay (ELISA) test
Time to First Asymptomatic or Symptomatic Venous or Arterial Thromboembolism in the Month Following the Diagnosis of Isolated HIT	24.9 Days Standard Error 2.8

Adverse Events

Isolated HIT

Serious events: 2 serious events

Other events: 0 other events

Deaths: 0 deaths

Serious adverse events

Serious adverse events
Measure	Isolated HIT n=10 participants at risk Hospitalized patients with isolated Heparin-Induced Thrombocytopenia (HIT), diagnosed by a fall in platelet count and a positive Platelet Factor 4 (PF4)-heparin Enzyme-Linked ImmunoSorbent Assay (ELISA) test
Respiratory, thoracic and mediastinal disorders Respiratory failure	10.0% 1/10 • Number of events 1 • Within 35 days (+/- 7) after the diagnosis of isolated HIT The study will collect data on thromboses and on bleeding events, the two types of adverse events most commonly associated with HIT and its treatment. Data will also be collected on all serious adverse events that are attributed as being possibly, probably, or definitely related to involvement in the study.
General disorders Other	10.0% 1/10 • Number of events 1 • Within 35 days (+/- 7) after the diagnosis of isolated HIT The study will collect data on thromboses and on bleeding events, the two types of adverse events most commonly associated with HIT and its treatment. Data will also be collected on all serious adverse events that are attributed as being possibly, probably, or definitely related to involvement in the study.

Other adverse events

Adverse event data not reported

Additional Information

Susan Assmann

New England Research Institutes

Phone: 617-923-7747

Email: [email protected]

Results disclosure agreements

Principal investigator is a sponsor employee
Publication restrictions are in place