Malignant hypertension: increased risk if no primary care doctor or failure to take medication.

Clinical bottom line (level 3b)

  1. Patients with hypertension were at increased risk for malignant hypertension if they:
    • had no primary care physician (NNH = 15 at unknown)
    • did not take their antihypertensive medication (NNH = 39 at unknown)
Shea et al: New England Journal of Medicine 1992; 327: 776-781
Zampaglione et al: Hypertension 1996; 27: 144-147
Expires August 2003

The study

Case-control study with objective outcomes, adjusted for confounding factors, not validated in an independent set of patients.

Setting: two acute inner-city hospitals, USA

207 patients (aged range 24 to 78 years, 69% male) malignant hypertension in Black or Hispanic patients

Excluded if
  • not black or Hispanic
  • ever admitted for acute MI, stroke, renal failure, aortic dissection, or pulmonary oedema


    • Cases: 93 patients (55% male, mean age 52): with malignant hypertension or hypertensive encephalopathy or severe, uncontrolled hypertension (mean blood pressure 221/141 mmHg)
    Controls: 114 patients (30% male, mean age 61): with hypertension (indicated by current drug treatment or a history of hypertension) admitted for conditions not related to hypertension. Matched for height, age, sex, but excluded if ever admitted for a hypertensive crisis

    Factors studied:
  • malignant hypertension


    • Factors summarised:
  • no primary care physician
  • noncompliance with antihypertensive regimen


    • Multiple regression analysis on risk factors (age, sex, race, ethnic background, education, smoking status, alcohol-related problems, use of illicit drugs).

    Outcomes studied:
  • malignant hypertension

    • 100% followed for uncertain length of time.

    The evidence

    Patient expected event rate for malignant hypertension: 3.0%
    risk factor for
    malignant hypertension     		adjusted OR
    (95% CI)    		 NNH
    (95% CI)
    no primary care physician 3.5
    (1.6 to 7.7)     		15
    (6 to 58)
    noncompliance with antihypertensive regimen 1.9
    (1.4 to 2.5)     		39
    (24 to 87)

    • 32% of patients had evidence of end-organ damage (grade III or IV retinopathy or new microscopic haematuria).

    Comments

    1. All patients were black or Hispanic. Controls were older and more were women. Controls also had less alcohol problems (p<0.01) and less illicit drug use (p<0.01).
    2. Roughly 3% of patients present with severe uncontrolled hypertension and associated complications to the emergency room (2).

    Citation

    1. Shea S, et al: Predisposing factors for severe uncontrolled hypertension in an inner-city minority population. New England Journal of Medicine 1992; 327: 776-781
    2. Zampaglione B, et al: Hypertensive urgencies and emergencies: prevalence and clinical presentation. Hypertension 1996; 27: 144-147
    Contributor: Nick Shenker and Chris Ball, August 2000
    Reviewer:

    Clinical Question.
    Patient hypertension
    Intervention or Exposure risk factors
    Outcome malignancy hypertension