1. Aetna considers automated ambulatory blood pressure monitoring medically necessary according to the selection criteria listed below, which are based, in part, on guidelines developed by the American College of Physicians.

   Note: Ambulatory blood pressure monitoring for more than 3 days is not considered medically necessary; repeat testing is not generally necessary more frequently than every 6 months.

   Member must meet any of the following criteria:

   1. Office or "white coat" hypertension: The physician suspects "white coat" hypertension or a transient rise of blood pressure that occurs in the office setting.  The member has blood pressure readings repeatedly elevated to a mild degree in the office setting (systolic readings of 140 to 150 mm Hg and/or diastolic readings of 90 to 99 mm Hg in adults, or greater than 90th percentile for age, gender and height in children (see appendix)) and no definitive diagnosis of hypertension has been established despite all of the following:

      1. Blood pressure measurements by non-physicians (e.g., nurse, technician) have been done and mild hypertensive readings have been obtained; and
      2. Member has repeated blood pressure measurements at home over at least 1 month, and the diagnosis of hypertension remains in question; and
      3. The physician has performed at least 3 blood pressure measurements at least 1 week apart in the office.
          
   2. Episodic hypertension: Ambulatory blood pressure monitoring is considered medically necessary for members whose symptomatology (paroxysms of excessive sweating, palpitations, apprehension) suggests episodic hypertension secondary to an adrenal tumor (e.g., pheochromocytoma), and office blood pressure measurements are repeatedly normal. 
   3. Evaluation of hypotensive symptoms: Ambulatory blood pressure monitoring is considered medically necessary for members with hypotensive symptoms and/or syncopal events that are thought to be related to anti-hypertensive medications.
   4. Evaluation of syncope: Ambulatory blood pressure monitoring is considered medically necessary when used in conjunction with a 24-hour Holter monitor (see CPB 0019 - Holter Monitors) to determine whether symptoms of syncope or near syncope are the direct result of an arrhythmia.
   5. Nocturnal angina: Ambulatory blood pressure monitoring is considered medically necessary to investigate blood pressure changes in members with nocturnal angina.
   6. Resistant hypertension: Ambulatory blood pressure monitoring is considered medically necessary prior to instituting an invasive investigation (e.g., renin vein assays, angiogram for renal artery stenosis) for secondary causes of hypertension for members with hypertension that is refractory to medications.
       

2. Aetna considers the use of ambulatory blood pressure monitoring experimental and investigational in any of the following situations because the medical literature does not support its use in these conditions:

   1. For blood pressure monitoring of persons with heart failure; or
   2. For blood pressure monitoring of pregnant women who do not meet any of the criteria listed above; or
   3. For diagnosing malignant (accelerated phase) hypertension. Under accepted guidelines, malignant hypertension requires urgent hospital admission for appropriate investigation and treatment; or
   4. For members with an irregular cardiac rhythm (e.g., atrial fibrillation).  Blood pressure readings are inconsistent and unreliable when an irregular cardiac rhythm is present due to variances in pulse volume; or
   5. For monitoring normal or borderline hypertensive blood pressure readings in the medical setting of members with documented evidence of end-organ damage (e.g., nephropathy, electrocardiographical changes, left ventricular hypertrophy, angina, myocardial infarction, cerebrovascular accident, transient ischemic attack) or cardiovascular risk factors (e.g., diabetes mellitus, smoking, hypercholesterolemia); or
   6. For routine monitoring to establish the clinical diagnosis of hypertension or to evaluate the member's blood pressure responses to treatment.

Automated ambulatory blood pressure (BP) monitoring is an outpatient procedure using fully automated devices to measure ambulatory BP at frequent intervals during the day and night in an effort to determine the variability of a patient's BP due to environmental stresses and to aid in definitively establishing a diagnosis of hypertension before committing the patient to life-long antihypertensive therapy.

Since treatment is rarely urgent in the absence of severe hypertension, the physician's diagnosis of hypertension should be substantiated first by repeated office readings by well-trained non-physicians.  If the diagnosis is not established by non-physicians taking BP measurement, a month trial of patient self-measurement of BP in the home at varying times during the day should be tried.

Patients with borderline hypertensive measurements in the office setting should have basic cardiovascular tests done.  Those who have evidence of target-organ damage or other cardiovascular risk factors should receive non-pharmacological and/or pharmacological treatments without further investigation.  Studies have unequivocally demonstrated that these patients have a significant risk of developing cardiovascular disease and will benefit from antihypertensive therapy.  Patients with no evidence of target-organ damage and no risk factors should be classified by a trial of self-measured BP; drug treatment should be considered for patients with consistently elevated readings in this setting.

The accuracy, patient acceptability and mechanical reliability of ambulatory BP devices remain controversial.  Studies have not shown that continuous ambulatory monitoring is superior to random, frequent patient self-measurement with a calibrated BP cuff.  In addition, data management and analysis have not been standardized and are arbitrarily determined.  Studies that showed the relationship between BP and cardiovascular disease risk and the clinical trials that documented the efficacy of antihypertensive drug therapy were based on casual office measurements.  Furthermore, the American College of Physicians recommends that a physician-measured diastolic BP reading of 90 to 99 mm Hg be utilized to establish a firm diagnosis of hypertension.

Automated ambulatory BP monitoring is not medically necessary for the diagnosis and management of hypertension in most patients; however, its use is indicated in rare subgroups of hypertensive patients with specific clinical problems, which are identified by the patient selection criteria indicated.

In a systematic review, Goyal and colleagues (2005) stated that "ambulatory blood pressure monitoring has established its use in the definition of white coat hypertension and monitoring of treatment of essential hypertension.  Any role for ambulatory blood pressure monitoring in heart failure is not well defined .... Prospective controlled studies on the impact of treatments on circadian blood pressure profile in congestive heart failure patients are needed".

Sorof and Portman (2000) reviewed their experience using ambulatory BP monitoring in children referred to a hypertension clinic to determine the frequency of pediatric white coat hypertension (WCH), which was defined by 3 different diagnostic criteria: (i) mean 24-hour BP less than Task Force-defined 95th percentile, (ii) mean 24-hour BP less than 95th percentile from pediatric normative ambulatory BP monitoring data, and (iii) mean 24-hour BP less than ambulatory BP monitoring 95th percentile and BP load (percentage of BP readings during 24-hour period exceeding the 95th percentile) less than 25 %.  Clinic BP values were available in 67 otherwise healthy children who underwent ambulatory BP monitoring; 51 had confirmed clinic hypertension by Task Force criteria.  Frequency of WCH in these 51 patients with the stated criteria was 53 %, 45 %, and 22 %, respectively. Elevated BP load was found in 52 % (12/23) of patients with normal mean BP.  The authors concluded that these findings suggested that many children referred for casual BP elevation have WCH even by strict diagnostic criteria.  Ambulatory BP monitoring may help differentiate WCH from persistent hypertension, thereby avoiding unnecessary diagnostic evaluation and identifying children most likely to benefit from early intervention.

Stergiou et al (2004) stated that office and out-of-office BP measurements are being used for the diagnosis of hypertension in children and adolescents.  The U.S. National Heart, Lung, and Blood Institute have recently presented a new classification of BP.  On the basis of office measurements the 90th, 95th and 99th percentile for gender, age and height are used to classify children and adolescents as normotensive, pre-hypertensive and stage-1 or stage-2 hypertensive.  Although auscultation using a standard mercury sphygmomanometer remains the recommended method, accumulating evidence suggests that ambulatory BP monitoring is useful for the detection of WCH and the prediction of target organ damage in children and adolescents.  Studies have shown ambulatory BP to be more reproducible than office measurements and normative tables for ambulatory measurements have been developed from cross-sectional studies in children and adolescents.  In regard to home measurements in children, there are limited data from small trials showing lower BP levels than daytime ambulatory BP.  The authors concluded that ambulatory BP monitoring is already finding a role as a supplementary source of information in children and adolescents, whereas at present home measurements should not be used for decision making in this population.

In a review and meta-analysis, Bliziotis et al (2012) examined the association of home BP measurements with target organ damage.  A PubMed and Cochrane Library search (1950 to 2011) revealed 23 studies reporting comparative data of home BP versus ambulatory and/or office measurements in terms of their association with several indices of target organ damage.  Correlation coefficients were pooled by random-effects model meta-analysis.  A total of 14 studies (n = 2,485) assessing echocardiographic left ventricular mass index (LVMI) showed similar correlations with home (coefficients r = 0.46/0.28, systolic/diastolic) as with ambulatory BP (0.37/0.26, p = NS for difference versus home BP), and superior to office measurements (r = 0.23/0.19, p < 0.001/0.009 for difference versus home BP).  Four methodologically heterogeneous studies assessing the glomerular filtration rate (n = 609) could not be pooled or lead to a concrete result.  Four studies assessing carotid intima-media thickness (n = 1,222), 3 assessing pulse wave velocity (n = 720) and 2 assessing urinary protein excretion (n = 156) showed no difference in pooled correlation coefficients with home versus office BP measurements.  With all the measurement methods SBP was more closely associated with target organ damage than DBP.  The authors concluded that these data suggested that home BP is as good as ambulatory monitoring and superior to office measurements in regard to their association with pre-clinical organ damage assessed by echocardiographic LVMI.  They stated that more research is needed to evaluate the relationship of home BP with other indices of target organ damage.

Swartz et al (2008) determined the cost-effectiveness of ambulatory BP monitoring in the initial evaluation of stage 1 hypertension.  Retrospective chart review of data for children referred to Texas Children's Hospital hypertension clinic between January 2005 and August 2006 was performed.  These investigators compared the costs of standard evaluations versus the initial use of ambulatory BP monitoring for children with clinic BP measurements suggesting stage 1 hypertension.  Charges for clinic visits, laboratory tests, and imaging were obtained from the Texas Children's Hospital billing department.  A total of 267 children were referred -- 139 children did not receive ambulatory BP monitoring; 54 met clinical indications for ambulatory BP monitoring but did not receive it because it was not a covered expense (44 children) or the family refused the study (10 children); 126 children received clinically indicated ambulatory BP monitoring, paid for either through insurance or by the family.  Fifty-eight children (46 %) had confirmed white-coat hypertension, 62 (49 %) stage 1 hypertension, and 6 (5 %) stage 2 hypertension.  With the observed prevalence of WCH, initial ambulatory BP monitoring use yielded net savings after evaluation of 3 patients, with projected savings of $2.4 million per 1,000 patients.  The authors concluded that ambulatory BP monitoring in the initial evaluation of suspected childhood hypertension is highly cost-effective.  Awareness of cost saving potential may increase the availability of ambulatory BP monitoring for evaluation of new-onset hypertension.

Muxfeldt et al (2012) stated that resistant hypertension is defined as uncontrolled office BP, despite the use of greater than or equal to 3 anti-hypertensive drugs.  Ambulatory BP monitoring (ABPM) is mandatory to diagnose 2 different groups, those with true and white-coat resistant hypertension.  Patients are found to change categories between controlled/uncontrolled ambulatory pressures without changing their office BP.  In this way, ABPM should be periodically repeated.  The aim of this study was to evaluate the most appropriate time interval to repeat ABPM to assure sustained BP control in patients with white-coat resistant hypertension.  This prospective study enrolled 198 patients (69 % women; mean age of 68.9 +/- 9.9 years) diagnosed as white-coat resistant hypertension on ABPM.  Patients were submitted to a second confirmatory examination 3 months later and repeated twice at 6-month intervals.  Statistical analyses included Bland-Altman repeatability coefficients and multi-variate logistic regression.  Mean office BP was 163 ± 20/84 ± 17 mm Hg, and mean 24-hour BP was 118 ± 8/66 ± 7 mm Hg.  White-coat resistant hypertension diagnosis presented a moderate reproducibility and was confirmed in 144 patients after 3 months.  In the 3rd and 4th ABPMs, 74 % and 79 % of patients sustained the diagnosis.  In multi-variate regression, a daytime systolic blood pressure less than or equal to 115 mm Hg in the confirmatory ABPM triplicated the chance of white-coat resistant hypertension status persistence after 1 year.  The authors concluded that a confirmatory ABPM is necessary after 3 months of the 1st white-coat-resistant hypertension diagnosis, and the procedure should be repeated at 6-month intervals, except in patients with daytime systolic blood pressure less than or equal to 115 mm Hg, in whom it may be repeated annually.

Vollebregt and colleagues (2013) stated that it is not known whether automated devices for measuring BP perform better than conventional sphygmomanometry in predicting preeclampsia.  In a prospective, observational, cohort study, these investigators compared 2 different automated devices with conventional sphygmomanometry for their association with development of preeclampsia or gestational hypertension.  A total of 289 healthy normotensive women of whom 235 were nulliparous and 44 parous with preeclampsia in a previous pregnancy were include in this study.  At 8 to 11 weeks of pregnancy, BP was measured with 2 different automated devices (continuous finger arterial pressure waveform registration and ABPM) and with conventional sphygmomanometry.  Main outcome measures were preeclampsia and gestational hypertension.  Blood pressure in the 1st trimester, as measured with all 3 methods, was significantly higher in women who developed preeclampsia or gestational hypertension.  After adjustment for previous preeclampsia, the point estimate of the odds ratios for association with later preeclampsia for both automated devices were comparable and higher than for conventional sphygmomanometry; however, differences were not statistically significant.  The odds ratio (95 % confidence intervals) for every 1 mmHg pressure increase of mean arterial pressure was 1.08 (1.02 to 1.15) for sphygmomanometry, 1.17 (1.09 to 1.27) for finger arterial pressure waveform registration, and 1.17 (1.07 to 1.27) for ABPM.  Results were comparable if preeclampsia and gestational hypertension were analyzed together.  The authors concluded that BP in the 1st trimester was associated with the development of hypertensive disorders of pregnancy; however, no significant differences were found between measurements by automatic devices including ABPM compared with conventional sphygmomanometry.

Appendix

Blood Pressure Levels for Boys by Age and Height Percentile. http://www.nhlbi.nih.gov/guidelines/hypertension/child_tbl.pdf.