History of Cardiac Surgery Increases Mortality Risk in Patients with ATAAD

Patients with acute type A aortic dissection (ATAAD) who have had prior cardiac surgery and are undergoing a “redo” have a greater risk of adverse events (AEs) compared with patients undergoing cardiac surgery for the first time, according to a recent study. Elizabeth Krebs, MD, of the University of Virginia in Charlottesville, presented the findings of the study at the Southern Thoracic Surgical Association 65th Annual Meeting & Exhibition.

Researchers analyzed on all patients undergoing operation for ATAAD in a Society of Thoracic Surgeons database between 2002 and 2017. Patients were classified by primary and redo sternotomy status. Researchers compared demographics, operative characteristics, outcomes, and cost data using univariate analysis, and they used multivariable regression models to evaluate risk-adjusted impact of redo status on outcomes. Researchers hypothesized that patients undergoing cardiac surgery again would have increased AEs compared with those undergoing first surgery. Primary outcomes were mortality, major morbidity, length of stay, and total cost.

Of 1,332 patients with ATAAD, 121 (9.1%) were undergoing reoperations. Redo patients tended to be older (63 vs 58 years; P<0.01) and had more comorbidities, including heart failure (16.5% vs 8.1%; P<0.01) and peripheral arterial disease (34.7% vs 15.7%; P<0.01). Intraoperative aortic valve replacement rates did not differ between the redo and first-time patients (26.5% vs 25.3%; P=0.78). The redo and primary groups also had similar rates of aortic arch procedures (25.6% vs 30.6%; P=0.25) and aortic root procedures (29.8% vs 36.9%; P=0.12). Those who had previously undergone cardiac surgery had higher rates of operative mortality (26.5% vs 15.7%; P<0.01), major morbidity (62.8% vs 55.8%; P=0.14), and need for reoperation (12.4% vs 9.0%; P=0.22). They also received more intraoperative red blood cell units (4 vs 1 g/dL; P<0.01), had longer lengths of stay (13 vs 10 days; P<0.01), and had more expensive total hospital costs ($73,430 vs $61,050; P=0.17). Strokes rates were slightly lower in the redo group (7.5% vs 9.4%; P=0.50).

“In looking at risk-adjusted association, for operative mortality, reoperative status was associated with an odds ratio of 2.14, or almost double the mortality ratio,” Krebs said.

“In looking at centralization across the regional network, we noticed a high degree of centralization, with 75% of cases performed at the six centers with the highest volume,” she said. “We also noted a high proportion of transfers in both groups, [at] around 60% in each group.”

The retrospective nature of the study is a limitation. Additionally, researchers only evaluated operative patients. “We do not have data on patients who were either managed medically or [died] prior to [reaching] the operating room,” Kreb said. The evaluated data were also limited to those included in the database.

The researchers concluded that redo status increases the risk for mortality and major morbidity. “These data should be considered when counseling patients and families prior to acute surgical intervention,” the study authors wrote.

The results are consistent with those of previous studies, Kreb said, but one major difference in is that researchers controlled for preoperative morbidities, “which had previously been implicated in this increase in mortality.”