Malignant hypertension: higher mortality and less haemodialysis with essential hypertension than glomerulonephritis.

Clinical bottom line (level 1b)

  1. Patients with malignant hypertension secondary to essential hypertension were more likely to die in the next five years than those with chronic glomerulonephritis.
  2. Patients with malignant hypertension secondary to chronic glomerulonephritis were more likely to require renal dialysis (NNF = 1 for unknown) , and far sooner than patients with essential hypertension (3.5 years sooner).
Kawazoe et al: Clinical Nephrology 1988; 29: 53-57
Expires August 2003

The study

Inception cohort study with objective outcomes, adjusted for confounding factors, not validated in an independent set of patients.

Setting: university hospital, Japan, 1971 to 1983

69 patients (aged mean 39 years, 80% male) with malignant hypertension: diastolic blood pressure > 120 mmHg and Grade III or IV hypertensive retinopathy

Excluded if
  • systemic renal diseases such as diabetes mellitus or collagen disease



    • Factors studied:
  • death, haemodialysis
  • essential hypertension (vs glomerulonephritis) chronic glomerulonephritis: history of acute or chronic glomerulonephritis; proteinuria +/- haematuria preceding the onset of hypertension (essential hypertension- exclusion of all other diagnoses)
  • essential hypertension (vs glomerulonephritis)




    • Multivariate analysis was used to adjust for sex, age, retinopathy and mean blood pressure.

    100% followed for mean 56 months
    Outcomes studied:
  • mortality
  • haemodialysis

    • The evidence

    outcome time to outcome number of patients/total number %
    (95% CI)
    mortality mean 56 months 9/69 13%
    (5.1% to 21%)
    haemodialysis mean 56 months / %
    (% to %)

    prognostic factor for
    mortality     		time to outcome unadjusted RR
    (95% CI)    		 NNF+
    (95% CI)
    essential hypertension (vs glomerulonephritis) mean 56 months inf
    (4.5 to inf)     		1
    (1 to 2)

    prognostic factor for
    haemodialysis     		time to outcome unadjusted RR
    (95% CI)    		 NNF+
    (95% CI)
    essential hypertension (vs glomerulonephritis) mean 56 months 0.19
    (0.09 to 0.39)     		-1
    (-2 to -1)

    • Time to haemodialysis (SD) (months) :
      • essential hypertension: 45 (9)
      • glomerulonephritis: 4 (1)
      • mean difference (95% CI): 41 (38 to 44)
    • In the multivariate analysis, significant factors were:
      • disease type
      • serum creatinine
    • Most patients were on haemodialysis within 18 months (>90%).
    • Causes of death: four strokes, two renal failure, one myocardial infarction, one dissecting aneurysm, one sudden death of unknown cause

    Citation

    1. Kawazoe N, et al: Long term prognosis of malignant hypertension: difference between underlying diseases such as essential hypertension and chronic glomerulonephritis. Clinical Nephrology 1988; 29: 53-57
    Contributor: Nick Shenker and Chris Ball, August 2000
    Reviewer:

    Clinical Question.
    Patient malignant hypertension
    Intervention or Exposure prevalence
    Outcome death