The Nineteenth NephJC went live on Jan 20th and 21st - marking the third time that we had two trans-Atlantic chats for the two different time zones. 

Clinical outcomes after parathyroidectomy in a nationwide cohort of patients on hemodialysis

Areef Ishani, Jiannong Liu, James B. Wetmore, Kimberly A. Lowe, Thy Do, Brian D. Bradbury, Geoffrey A. Block, and Allan J. Collins

PMID: 25516915

North and South American #NephJC chat Tuesday Jan 20th, 9 pm EST

Europe and Africa #NephJC chat: Wednesday Jan 21 8 pm GMT

This month is a CJASN/Parathyroid special! Firstly, the #cJASNeJC is discussing a related article - the DOPPS study on the trends of management of hyperparathyroidism. That serves as good background material for the article we will be discussing on #NephJC. There is also a very erudite editorial accompanying these two articles, which goes through the therapeutic dilemma we face treating such patients.

The article we will be discussing on #NephJC looks at the outcomes of parathyroidectomy in patients who have been on hemodialysis longer than a year.

Objective:

The objective of this study was to evaluate morbidity and mortality after a parathyroidectomy by comparing event rates in the year immediately after parathyroidectomy with rates in the year immediately preceding it.

Methods:

Inclusion Criteria:

  1. Patients over 18 years of age.
  2. On hemodialysis for at least one year before undergoing parathyroidectomy.
  3. Underwent parathyroidectomy in the three years, between January 1, 2007 and December 31, 2009.
  4. Patients had to have Medicare as the primary insurance payer for both Part A & Part B.

Outcomes:

These were captured over three distinct periods:

  • Immediate hospitalization post-parathyroidectomy.
  • Short-term, defined as 30 days post discharge
  • Long term, defined as one year post discharge for parathyroidectomy.
    • For this last period, they used the one-year prior as the control period. So, events in the year prior to parathyroidectomy were compared to events in the year following parathyroidectomy, with patients serving as their own control.

The actual outcomes were

  • All-cause mortality

  • Hospitalization events

    • Total number

    • Specific causes

    • ICU stay

    • Emergency department visits

    • Outpatient visits for hypocalcemia

  • Fractures

Results:

 4,435 patients were selected from a total of 7,707 patients after applying exclusion criteria (see figure 1 from paper for details).

Parathyroidectomy was associated with significant morbidity and 2% short-term mortality. We find this is a rather harrowing result: 41 (0.9%) patients died during the index hospitalization, and 48 (1.1%) patients died within 30 days after discharge.

Parathyroidectomy was also associated with high re-hospitalization rates and more intensive care unit and emergency room visits requiring treatment for hypocalcemia compared with the preceding year. Hospitalizations were significantly higher for stroke, acute myocardial infarction and dysrhythmia.

Figure 2 from the article: Most of the secondary outcomes, which were higher in the year after parathyroidectomy compared to the year before. 

Figure 2 from the article: Most of the secondary outcomes, which were higher in the year after parathyroidectomy compared to the year before. 

For fractures, there was no difference.

In addition, in subgroup analyses, older white men with comorbid conditions did worse (Figure 3). Lastly, in sensitivity analysis, there was no difference if patients underwent total versus partial parathyroidectomy. There is supplemental data available, which presents the outcomes as rate difference, rather than RR.

Strengths:

They used a nationwide cohort of patients receiving dialysis who underwent PTx during a contemporary period. Because of the pre-post design, results are not limited by selection bias.

Study evaluated patient oriented outcomes and can serve as the basis for counseling patients regarding outcomes should they elect to pursue PTx.

Some Limitations:

The study fails to provide the indications (other than an elevated PTH) for performing parathyroidectomy and the long-term follow-up of the surviving patients after 1 year.

The study was sponsored by AMGEN and refers to the procedure as “surgical parathyroidectomy,” subtly implying that a medical parathyroidectomy, with cinacalcet (which was approved in March 2004), is an alternative.

Before and after controls – comparator group is patients themselves (not patients with hyperparathyroidism who did not undergo parathyroidectomy).

Discussion:

Although they were unable to provide a comprehensive risk-benefit analysis of parathyroidectomy with the present data, the new information they report contributes to the understanding of the risks involved, assisting providers and patients in making informed decisions.

NephJC summary written by Teerath Kumar (@teerath1978), Nephrology Fellow, University of Ottawa.

Join us on Jan 20th 9 pm EST or Jan 21st at 8pm GMT for the next #NephJC discussion.