Case #1 Answers:
The history, physical examination, and laboratory evaluation of the patient with chronic hypertension are focused on answering three questions:
1. Does the patient have a secondary, potentially curable form of hypertension?
2. Does the patient have target organ cerebrovascular, cardiac, or renal disease?
3. Does the patient have other cardiovascular risk factors?
The history therefore should include the following issues in addition to that contained in the case:
It is essential that blood pressures are accurately recorded. The American Heart Association recommends two or more blood pressure measurements separated by two minutes. Cuff size adequacy must be ensured. The blood pressure should be verified in the contralateral arm to detect obstructive vascular disease that may lower blood pressure in the left arm, thus giving an inappropriately low estimate of the blood pressure to which the brain and heart are exposed. If pressures are discrepant, the higher one should be used.
The thrust of this question is the need to consider the possibility that the patient is a clinic responder or has white coat hypertension. This problem may be present in as many as 25% of all patients labeled as chronically hypertensive. It is important for the resident to understand that an isolated elevated blood pressure in a physician's office does not in of itself make the diagnosis of chronic hypertension. If there is concern about white coat hypertension, home blood pressure monitoring or 24 hr ambulatory blood pressure testing should be considered.
The important point here is that the physician should not come immediately to the diagnosis of hypertension but should obtain multiple blood pressure readings over the ensuing one to two months. The patient should be educated about the possibility that he/she has chronic hypertension, the medical implications thereof and the need for followup. You may wish to proceed with non-pharmacologic interventions.
Stage 1 chronic hypertension is now well established. Please note that the terms mild, moderate and severe are no longer recommended. A primary reason is that most patients who suffer cardiovascular consequences of hypertension have stage 1 disease (i.e. it is the most common) and the JNC 7 experts felt that it may be misleading to label this as "mild". See Table 1 page 2561 of the JNC 7 report.
Patient education is a critical aspect of the management of chronic hypertension, particularly so because the condition is asymptomatic in most patients. Patients should be informed of the diagnosis and made aware that the risk of stroke, heart attack and kidney failure are several fold higher than people with normal blood pressure. The patient should be told that the reduction of blood pressure with lifestyle changes or medication will substantially reduce the risk of adverse outcome. He/she should be informed that chronic hypertension is a life long problem, although with appropriate management, normal levels of blood pressure can be obtained. It is also valuable to tell the patient that once blood pressure is brought under control, visits to the physician may not be necessary more than every 6 to 12 months.
The JNC 7 recommendations for laboratory evaluation of patients thought to have essential hypertension include the following tests:
The first phase of treatment is always non-pharmacologic management, difficult though it may be. These include:
Emphasize to the resident that hypertension is simply one of many cardiovascular risk factors. Therefore, an integral part of managing hypertension is addressing other risks for stroke or myocardial infarction. It should also be stressed that there is no urgency to initiate pharmacologic therapy in patients without diabetes or end-organ disease. It is reasonable to start with a 3-6 month period of lifestyle modification prior to embarking upon drug therapy in these patients.
In the recently completed Hypertension Optimal Treatment (HOT) trial, 19,000 hypertensive patients were treated to lower diastolic blood pressure to 85-90; 80-85 or less than 80 mmHg. The main conclusion was that the optimal blood pressure was approximately 138/83 mmHg (reasonable targets are therfore 130-140/80-85). Further reduction had no additional effect on cardiovascular risk. Of note, is that there was no significant evidence of increased cardiovascular events in those with known CAD at lower levels of pressure, i.e., no J-curve phenomenon. A subgroup analysis in diabetic patients indicated that cardiovascular risk was lowest in those with diastolic less than 80 mmHg.
There is compelling evidence indicating that diuretics are at least as good – and in some cases better – at reducing cardiovascular morbidity and mortality than other agents (see ref 4, Psaty et al who conclude that diuretics are clearly the best agent). JNC 7 recommends a diuretic for most patients unless there is a compelling indication for an alternative. Note that beta blockers are included as a first line agent for most patients. Reference 4 provides evidence that beta blockers are inferior to thiazides and these authors recommend that beta blockers be considered a second line.
There are obviously no single correct responses for these scenarios. The following are my own suggestions.
a. Hydrochlorothiazide 12.5 mg/day. Note that a 1998 meta-analysis by Messerli et al strongly suggest that beta-blockers, as single agents, are not effective therapy in the elderly.
b. I would avoid a beta-blocker because of the asthma. Verapamil, and perhaps diltiazem, may have negative effects on cardiac output. Risks of volume depletion and/or hyponatremia during exertion may argue against a diuretic. An ACE inhibitor would be a reasonable choice.
c. Atenolol 50 mg per day is an effective and inexpensive choice given the angina. A long acting calcium channel blocker would be a pricey alternative.
d. In previous years, terazosin would have been a good first choice. However, because results of the ALLHAT trial (reviewed in ref 4) demonstrate an increase risk of CHF in patients given alpha blocker as their initial anti-hypertensive, alternative agents should be selected as the 1st drug. Since diuretics may aggravate urinary symptoms (although 12.5 mg would have minimal such effects and would be worth a try), an ACE inhibitor would be reasonable. It appears that addition of alpha blockers, as a 2nd or 3rd agent, is a safe approach.
Monthly cost to the patient and side effects of major antihypertensives:
a. hydrochlorothiazide 25 mg QD
- $9.00 ($4.50 /month if you prescribe 12.5 mg/day and used the scored tablet that can be split in half)
- hypokalemia, hyponatremia, azotemia, hyperuricemia, gout, hyperglycemia, alkalosis, increased total and LDL cholesterol, impotence; skin photsensitvity, postural hypotension ; metabolic effects less common and less important in their magnitude at lower (12.5-25 mg) doses.
b. hydrocholorothiazide 25mg/triamtere 37.5 mg QD
- similar to hydrochlorothiazide except may cause hyperkalemia especially when used with an ACE-I or angiotensin II receptor blocker.
c. atenolol 50 mg QD
- fatigue, weakness, insomnia, sexual dysfunction, bronchospasm, bradycardia, heart block, increased serum triglycerides
d. captopril 25 mg bid
- cough, headache, angioedema (rare), hyperkalemia, worsening of renal function especially in patients with renal artery stenosis
e. lisinopril (Zestril;Prinivil) 10 mg QD
- as for captopril
g. diltiazem long-acting 120 mg QD
- $60 or more depending on if generic or trade name drug
- fatigue, constipation, peripheral edema, bradycardia, congestive heart failure, feeling of warmth
h. nifedipine long acting (Procardia XL) 30 mg QD
- dizziness, headache, flushing, peripheral edema, tachycardia,
i. terazosin 5 mg QD
- $ 42 for generic; $67 for trade name (Hytrin)
postural hypotension, dizziness, fatigue, headache, nasal congestion