Despite changes in medical therapy for secondary hyperparathyroidism (SHPT), rates of parathyroidectomy (PTx) have remained stable in recent years, a new study finds.
Previous research on PTx trends narrowly focused on Medicare recipients, so Glenn M. Chertow, MD, of Stanford University in Palo Alto, California, and his team sought to obtain a broader view using the Healthcare Cost and Utilization Project’s Nationwide Inpatient Sample, a national database representing a fifth of US hospitals serving patients of all ages and insurance types, including the uninsured. They looked for trends from 2002 to 2011 in PTx, in-hospital mortality, length of stay, and hospitalization costs.
Excluding cancer cases, surgeons performed 32,971 PTx for SHPT during the period. Overall, the rate for PTx was approximately 5.4 per 1000 patients, using dialysis and transplant recipient counts from US Renal Data System reports as the denominator.
Results showed that PTx rates rose from 7.3 to 7.9 procedures per 1000 patients from 2002 to 2003, declined to a low of 3.3 procedures per 1000 patients in 2005, then rebounded before becoming stable from 2006 onward, with rates of 5.4, 5.5, 5.6, 4.4, 4.8, and 4.9 per 1000 patients observed in years 2006, 2007, 2008, 2009, 2010, and 2011, respectively.
Dr Chertow and colleagues attributed the abrupt decline in PTx to the introduction of cinacalcet. “During 2004 and 2005, clinicians might have deferred parathyroidectomy in some patients, anticipating improved control of sHPT,” they wrote in an online report in the Clinical Journal of the American Society of Nephrology.
Unlike the current findings, the Evaluation of Cinacalcet HCl Therapy to Lower Cardiovascular Events (EVOLVE) trial found a sizeable drop in PTx with cinacalcet compared with placebo. EVOLVE specified titration of cinacalcet to a maximum daily dose of 180 mg during the first 20 weeks that rarely occurs in clinical practice, the investigators noted. Release of SHPT guidelines also may have influenced PTx trends.
Rates of in-hospital mortality decreased from 1.7% in 2002 to 0.8% in 2011. In the current study, in-hospital mortality rates were significantly higher in patients with heart failure and peripheral vascular disease and lower among patients with prior kidney transplants. The study lacked information on patients’ SHPT severity. Lengths of hospital stay decreased over time, whereas PTx costs increased.
In an accompanying editorial, James B. Wetmore, MD, of the Minneapolis Medical Research Foundation, commented that the risk to benefit ratio of PTx might be more unfavorable than anticipated in light of mortality, treatment failure, and the prospect of hypocalcemia.
“The nephrology community should engage in a robust discussion about the appropriate role of PTX in patients on maintenance dialysis with SHPT,” Dr Wetmore stated. “More work is needed examining which types of patients might benefit from PTX, such as those likely to live longest, and which types might incur undue risk, such as those who are nonadherent with therapy and who may be at elevated risk of life-threatening adverse events after surgery.”
Among the disclosures, Dr Chertow noted research support from Amgen, Inc., the manufacturer of cinacalcet (Sensipar®).