Anemia Present in More than Half of TAVR Patients, Raises Long-term Mortality
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Preoperative anemia is present in more than half of patients receiving transcatheter aortic valve replacement (TAVR), increasing the risk of mortality within 1 year. Results of the 10-center, observational trial were published online November 26, 2013, ahead of print in Circulation: Cardiovascular Interventions.
Researchers led by Peter P. de Jaegere, MD, PhD, of ThoraxCenter (Rotterdam, The Netherlands), looked at 1,696 patients with aortic stenosis undergoing TAVR from November 2005 to March 2013 at 10 centers worldwide. Patients received the CoreValve System (Medtronic, Minneapolis, MN), the Sapien or Sapien XT (Edwards Lifesciences, Irvine, CA), or the Direct Flow Valve (Direct Flow Medical, Santa Rosa, CA).
Preoperative anemia (Hb level < 12.0 g/dL in women, < 13.0 g/dL in men) was present in more than half (57%) of the cohort, ranging from 42% to 67% at participating hospitals. Mean preoperative Hb concentration was 12.1 ± 1.7 g/dL.
Patients with anemia were older (81 vs. 80 years; P < 0.001), more frequently male (56% vs. 47%; P < 0.001), and had a lower BMI (26.3 vs. 26.8 kg/m2; P = 0.049). They also more frequently had NYHA class ≥ III (86% vs. 81%; P = 0.002), more peripheral vascular disease (32% vs. 23%; P < 0.001) and a higher estimated operative risk (logistic EuroSCORE 21% vs. 17%; P < 0.001).
On multivariable logistic regression analysis, preoperative anemia was associated with a trend toward 30-day mortality (OR 1.72; 95% CI 0.96-3.12; P = 0.073), and was associated with increased mortality at 1 year (OR 1.42; 95% CI 1.12-1.81; P = 0.004). One-year mortality was 21% in patients without anemia vs. 31% in patients with anemia (P < 0.001). In addition, an inverse relationship was found between the severity of preoperative anemia (ie, serum Hb level) and 1-year mortality, especially in patients with an Hb < 10.0 g/dL (HR 2.78; 95% CI 1.60-4.82; P < 0.001).
Blood Transfusions Key
During or after TAVR, 694 patients (41%) underwent at least 1 blood transfusion. Patients with anemia consistently had at least 1 unit of blood transfused twice as frequently before and at each time interval measured after TAVR (24 and 72 hours) compared with patients without anemia (P < 0.001). Nevertheless, the indication for blood transfusion was more often not related to an overt bleeding source in patients with anemia (60% vs. 46%; P < 0.001). The most frequent indication for transfusion therapy in patients with anemia was operative blood loss (19%), while the most frequent indication in patients without anemia was access site complications (7%).
Regardless, every unit of transfused blood was associated with a 25% increase in risk of 30-day mortality (95% CI 1.08-3.67; P = 0.004), a risk which lessened to 9% for long-term mortality (95% CI 1.03-1.14; P = 0.001).
Older Age, Comorbidities May Explain Anemia
According to the authors, the prevalence of anemia in this cohort is higher than that found in patients with ACS or congestive heart failure as well as those undergoing PCI or cardiac surgery. “This is most likely explained,” they note, “by differences in patient characteristics. Patients who are referred for [TAVR] are older and, therefore, more often have associated cardiac and noncardiac chronic disease or comorbid conditions, which both may explain a higher prevalence of anemia in these patients.”
Dr. de Jaegere and colleagues add that factors associated with anemia in the present analysis are common in patients with anemia and frequently seen in patients who undergo TAVR. These include:
- Chronic kidney disease, found in 60% of patients in the current study
- Heart failure, 57%
- PVD, 28%
- Malignancy, 12%
“A prevalence of 57% of anemia is, therefore, not surprising,” they assert. “The information of the presence of anemia and its associated conditions may help to improve patient selection and planning of [TAVR]. It is conceivable that the optimization of some of the baseline conditions that are associated with anemia may positively affect outcome (eg. optimization of heart failure, prehydration).”
In particular, the authors write, “the biggest gain is to be expected from a more restrictive use of blood transfusions in addition to the need [for] uniform criteria for the use of blood products.”
Correct Anemia, Avoid Transfusions
In an e-mail communication with TCTMD, Eugenia Nikolsky MD, PhD, of Rambam Medical Center (Haifa, Israel), acknowledged that anemia is prevalent among the elderly, and the reasons are multifactorial, ranging from worse renal functioning to increased incidence of H. Pylori. Nevertheless, [more than] 50% prevalence of patients being anemic in this TAVR registry is really high,” Dr. Nikolsky said. “This is an interesting and important finding, especially knowing the association of anemia with worse prognosis. One of the reasons for this is that patients who are referred for TAVR are those who were turned down by the cardiac surgeons and by definition are patients with multiple comorbidities, and therefore these conditions . . . are likely very prevalent among this population.”
Nevertheless, preoperative anemia should not automatically serve as a contraindication for TAVR, she noted. “In my opinion, this decision should be based on an individual basis (like for every patient candidate for TAVR who needs comprehensive assessment of multiple variables that are taken into account for decision making),” Dr. Nikolsky said. “Anemia needs to be one of the factors in the entire decision making process. Optimally, the reason for anemia should be clarified preprocedurally. Some types of anemia may be easily diagnosed by simple blood tests and/or instrumental methods and corrected (treatment with B12, folic acid, iron, erythropoietin, PPIs, etc.). Correction of anemia before TAVR, if possible, may lead to avoiding unnecessary blood transfusion post procedure, which has negative prognostic value—this was elegantly shown in the paper.”
Source:
Nuis RJ, Sinning J-M, Rodés-Cabau J, et al. Prevalence, factors associated with, and prognostic effects of preoperative anemia on short- and long-term mortality in patients undergoing transcatheter aortic valve implantation. Circ Cardiovasc Interv. 2013;Epub ahead of print.
Disclosures:
- Dr. de Jaegere reports serving as a physician proctor for Medtronic CoreValve.
- Dr. Nikolsky reports no relevant conflicts of interest.
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