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For those patients on dialysis, the appropriate tubes can be given to the dialysis unit staff. The staff at the dialysis unit can draw the patient’s serum for the clinical center. Blood should be drawn pre-hemodialysis; however, patients supported with peritoneal dialysis or a kidney transplant can have their blood drawn at any time. The center can then send the tubes to the CBL for processing (central measure) or process the sample at the center (local measure).
March 25, 2004 29 Informed Consent To enroll in the AASK Cohort Study, individuals must provide written informed consent.
Sample consent forms will be developed. Clinical center PIs can adapt these forms as needed to meet the requirements of local IRBs. For participants who have not reached ESRD, a typical consent process would include two consent forms, one that covers the basic elements of the cohort study (contact pattern and data collection elements except for DNA) and a separate consent form for collection of DNA. For participants who have already reached ESRD, only the consent form for DNA will be used. Additional consent forms may be required to cover additional procedures that are not covered in the original consent.
Blood pressure will be measured in a standardized fashion by trained, certified observers using the Tycos Classic Hand Aneroid device. These measurements will be used to guide antihypertensive drug therapy for those patients who have not reached ESRD. While the general approach to blood pressure measurement will be identical to that used in the AASK trial, we decided against continuation of the Hawksley MKII random-zero device in the Cohort because the American Hospital Association and the Environmental Protection Agency have proposed to eliminate mercury from hospitals. We also decided against electronic devices, because these devices use an oscillometric technique. In contrast, aneroid devices use the auscultatory technique that was used during the trial.
AASK participants who have not reached ESRD will be encouraged to have their blood pressure managed by AASK Cohort investigators and staff. The target blood pressure is based upon prevailing guideline (specifically, JNC VII guidelines), while selection of first line therapy is based on the results of the AASK trial. An algorithm for stepwise blood pressure control has been developed, along with specific suggestions for replacement of medications used in the AASK trial for medication to be used in the Cohort Study. Drugs listed as part of the algorithm March 25, 2004 30 will be offered free of charge to the participant. However, there will be investigator latitude. If other drugs are used to control blood pressure, the investigator, patient’s insurance company or the participant will need to cover these costs. Once a participant reaches ESRD, blood pressure management will be the responsibility of the patient’s nephrologist rather than the AASK team.
The AASK team may continue to provide drugs listed as part of the algorithm free of charge on a compassionate care basis. However, the provision of medications is not mandatory, because the investigators at that point will not have primary responsibility for blood pressure control.
Provision of antihypertensive care to the AASK Cohort Study participants has scientific, practical, and ethical roles. The scientific role is to directly control two of the major ‘known’ determinants of kidney disease progression (treatment of hypertension and use of renoprotective, antihypertensive medication). In this fashion, we will test our research hypotheses in the setting of recommended antihypertensive care. The practical role is to promote retention of individuals who otherwise might not participate in the Cohort Study after the trial ends. The ethical role is to avoid the situation of studying the impact of inadequately treated hypertension among individuals who received excellent care in the trial yet have inadequate resources to cover their own care after the trial ends. Note that the Cohort Study is neither designed nor powered to compare the effects of different antihypertensive agents on renal function or cardiovascular disease outcomes.
The recommended blood pressure goal during the cohort phase of AASK is a systolic blood pressure 130 mmHg and a diastolic blood pressure 80 mmHg. This goal corresponds to national guidelines (JNC VII, 2004 and NKF, 2003) published after the initiation of the AASK Cohort Study.
The recommended approach to antihypertensive drug therapy is based upon the results of the
AASK trial, which documented that:
• ACEI-based therapy was superior to CCB-based therapy, at least in patients with proteinuria ( 0.22 mg protein/mg creatinine), and perhaps among those with lesser degrees of proteinuria,
• ACEI-based therapy appears to be superior to beta-blocker therapy, irrespective of
Table 6 (below) summarizes the use of medications in both the AASK trial (completed) and the recommended approach to medications in the AASK Cohort Study. In contrast to the AASK trial, which rigidly controlled and monitored the BP management protocol, investigators will have more discretion. Still, investigators will be encouraged to follow broadly the approach outlined below and to follow general prescribing recommendations for these medications.
*Provided by manufacturer with financial support **Provided by manufacturer ***Purchased Specific considerations might influence the selection of medication. The following is a partial list of such considerations that generally should be based on well-accepted principles of care as
outlined in JNC VII:
For participants who had developed an ACEI-related cough in the trial or who subsequently
For participants who have had a myocardial infarction or who develop a myocardial infarction, a beta-blocker should be used.
For patients with heart failure or with impaired left ventricular function, doxazosin should be avoided.
Participants are offered free management for their hypertension as part of the AASK Cohort study. Hypertension management will include provision of antihypertensive medications and visits with AASK staff and investigators. Quarterly visits (one every three months) are anticipated. An additional two visits for blood pressure management (total of 6 visits per year) could be offered in order to achieve or maintain blood pressure control. Additional visits beyond these six visits are at the discretion of the local investigator who might, for example, refer the participant back to his/her personal physician for a work-up of secondary hypertension.
The medications listed in Table 6 of this section are offered free to the participants. Sources of medications include donations from pharmaceutical companies (e.g. ramipril from Monarch) and purchase of other medications (e.g., Lasix, HCTZ) from clinical center funds. Reimbursement of other medications may be pursued, potentially through insurance company reimbursement if the participant has health insurance that covers medication costs.
At a practical level, the following is a reasonable approach to transition patients from AASK trial
Patients Assigned to Beta-Blocker. Taper beta-blocker per PI’s instructions while simultaneously adding Ramipril.
Questionnaires Questionnaires are administered annually that focus on potential exposures of interest and on surveillance for outcomes (ESRD and cardiovascular outcomes). Exposures include health habits (alcohol, smoking, analgesic use, drug use), exposure to IV contrast, and psycho-social factors. Instruments to be used will include, where possible, questionnaires used in the AASK trial (SF-36) and standardized instruments used in other studies, including the Jackson Heart Study. Psychosocial questionnaires will include the SF36, the Approach to Life, the Beck Depression Inventory II, and the Diener Satisfaction of Life Form. A sleep questionnaire will be administered twice.
Medications At each visit, types of antihypertensive medications and types of other concurrent medications are collected using procedures developed in AASK.
For patients who reach ESRD during the Cohort Study, types of antihypertensive medications and types of other concurrent medications are collected at each visit. Due to the large number of common medications that many ESRD patients take, the transplant/dialysis facility will be requested to fax a copy of the patient’s most recent medication sheet as a secondary data collection tool. This will include the dose and route of IV/Subq medications such as EPO/aranesp, vitamin D (Calcijex, Zemplar, Hectoral).
On an annual basis, fasting lipids [total cholesterol, LDL cholesterol (calculated), HDL cholesterol and triglycerides], glucose, insulin, routine chemistry panel and CBC will be measured. Other analytes will include C-reactive protein (CRP), and potentially other measures of inflammation, measures of oxidative stress and novel lipid risk factors damage, e.g. Lp(a).
To monitor the effects of antihypertensive drug therapy, local laboratories (e.g. electrolytes) will be obtained as needed at the discretion of the clinical center PI.
DNA DNA will be collected once. Blood will be shipped to the AASK Genetics Core Laboratory at Mt. Sinai Hospital by overnight mail. When received, blood will be divided into 3 aliquots: 10 ml will be used to isolate genomic DNA; 10 ml will be used either to immortalize lymphocytes or for controlled freezing of 4 aliquots of purified PBMC; approximately 50 ul will be spotted onto IsoCode Stix (Schleicher & Schuell) and dried as an archive for future DNA isolation/sample identification/quality control.
24-Hour Urine Collection Once each year, a 24-hour urine collected will be obtained. Analytes will include creatinine, protein, albumin, sodium and potassium. From each collection, aliquots will be stored.
Finger Nails Finger nails will be collected once each year. Participants will be asked to trim each of their 10 fingers with a chromium-free nail clipper (to be provided) and will be asked to put the clippings in a labeled plastic bag. The bags will be stored at room temperature and then shipped to the Central Biochemistry Laboratory at the Cleveland Clinic. The Laboratory for Instrumental Neutron Activation Analysis, part of the Interfaculty Reactor Institute of Delft University of Technology (Delft, The Netherlands) can perform these analyses, as it has done for other cohort studies. The neutron activation analyses provides measurements of 50 heavy metals, including
Electrocardiogram A central ECG will be obtained at C0, C24 and C48. A copy will be retained for local reading and the original sent to the Cardiovascular Procedures Core Laboratory at Lenox Hill Hospital for central coding. Specific codes of interest are the presence of LVH and myocardial infarction.
A local ECG will be obtained at C12, C36 and C60.
At baseline (C0) and at years 2 and 4 (C24 and C48) a “limited” echocardiogram will be obtained to measure left ventricular mass. This 2-dimensional-directed, M-Mode echocardiogram will record LV septal thickness, LV posterior wall thickness and LV dimensions (separately, during systole and diastole). The Cardiovascular Procedures Core Laboratory at Lenox Hill Hospital will serve as central reading facility for the study.
Ambulatory BP Monitoring
At baseline (C0) and at years 2 and 4 (C24 and C48), 24-hour ambulatory blood pressure recordings will be obtained. The study will use the SpaceLabs™ 90217 Ultralite or SpaceLabs™ 90207 devices. For each 24-hour recording, measurements will be obtained every 30 minutes through the day and night, from which awake and asleep averages will be calculated, along with other variables including dipping status.
Method of Renal Replacement Therapy (RRT) For participants who reach ESRD, data will be recorded at each annual visit to verify and update the method of RRT (cadaveric transplant, living related donor, hemodialysis and its frequency, peritoneal dialysis (CCPD, CAPD, other)).
March 25, 2004 36 Renal Outcomes: The primary clinical outcome for analyses that include the period of the
AASK Cohort Study will be a composite outcome defined by the occurrence of:
Confirmed doubling of serum creatinine (as measured centrally on specimens from 2 visits) or ESRD (dialysis or transplantation) or Death The inclusion of deaths as part of the composite outcome will reduce the risk of informative censoring. In most instances, parallel analyses will be performed in which deaths are not included as part of the composite outcome. For analyses that focus on the outcomes during the trial period when GFRs were collected (Period 1), the composite outcome will be based on a 25 ml/min/1.73m2 or 50% reduction in GFR from baseline (rather than a doubling of serum creatinine).
For mechanistic analyses of longitudinal change in kidney function, the primary outcome will be the slope of GFR change in which GFR is estimated from the 3-variable AASK prediction equation that includes serum creatinine, sex, and age.
For analyses of proteinuria, the outcomes will include a continuous outcome defined by the urine protein/urine creatinine ratio (UP/Cr) and 2 binary outcomes [a UP/Cr 0.22 (roughly 300 mg/d of proteinuria) and a UP/Cr.66 (roughly 1 gm/d of proteinuria)].
Note that confirmation of a doubling of serum creatinine is required. That is, once a follow-up creatinine measurement documents a doubling of creatinine, a repeat creatinine must confirm the initial ‘doubling’.
Cardiovascular Outcomes: Clinical cardiovascular outcomes is classified as either ‘definite’ or ‘probable’ as defined below. The category of ‘total’ cardiovascular outcomes is defined as the occurrence of either a ‘definite’ or ‘probable’ cardiovascular outcomes. In most analyses, cardiovascular outcomes are grouped together as a composite outcome; however, in some instances, cause-specific cardiovascular events are outcomes of interest.