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Follow-up on the SYNTAX trial at 5 years continues to paint a rosy picture for bypass surgery. Also this week, taking gender differences into account before aortic valve repair.
SYNTAX at 5 Years Still Points to CABG
Five-year follow-up of the SYNTAX trial confirms that coronary artery bypass graft (CABG) surgery for complex disease should remain standard care for patients with high or intermediate (≥23) SYNTAX scores, researchers said in The Lancet.
The 5-year results of the combined primary endpoint of death, stroke, myocardial infarction, and repeat revascularization was 26.9% for CABG and 37.3% for percutaneous coronary intervention (PCI), reported Friedrich W. Mohr, MD, of Herzzentrum Universität Leipzig in Leipzig, Germany, and colleagues. The results were significant at P<0.001.
Five-year outcomes for events for CABG versus PCI were:
- MI -- 3.8% versus 9.7% (P<0.0001)
- Repeat revascularization -- 13.7% versus 25.9% (P<0.0001)
- All-cause death -- 11.4% versus 13.9% (P=0.10)
- Cardiac death -- 5.3% versus 9% ( P=0.003)
- Stroke -- 3.7% versus 2.4%, (P=0.09)
For death/stroke/MI combined the outcomes were 16.6% for CABG versus 20.8% for PCI (P=0.03).
However, for "patients with less complex disease (low SYNTAX scores, <22) or left main coronary disease (low or intermediate SYNTAX scores), PCI is an acceptable alternative," researchers concluded.
SYNTAX Score II Bridges Gaps
To personalize the broad anatomical SYNTAX score, researchers devised a method that included clinical characteristics of patients to determine 4-year mortality risk differences between CABG and PCI, Patrick W. Serruys, MD, of the Thoraxcenter, Erasmus University Medical Center in Rotterdam, the Netherlands, and colleagues reported in The Lancet.
In the new SYNTAX II score, eight predictors of long-term death emerged: original SYNTAX score, age, creatinine clearance, left ventricular ejection fraction, presence of unprotected left main coronary artery disease, peripheral vascular disease, female sex, and chronic obstructive pulmonary disease.
"The SYNTAX score II significantly predicted a difference in 4-year mortality between patients undergoing CABG and those undergoing PCI," Serruys and colleagues wrote .
Diabetes was not important in this model for determining whether CABG or PCI would be better for patients. They concluded that "SYNTAX score II can better guide decision making between CABG and PCI than the original anatomical SYNTAX score."
Other researchers in 2011 devised a "functional" SYNTAX score to improve upon the original.
Sex Differences Affect TAVI
The aortic root is a complex three-dimensional structure, made even more challenging by area differences between women and men undergoing transcatheter aortic valve implantation (TAVI), researchers said.
CT angiography imaging of 97 women and 80 men (mean age 82) showed that women had a significantly smaller annular area (387 versus 483 mm2, P=0.0002) and left ventricular outflow tract dimension (374 versus 478 mm2, P=0.0024), but with similar elipticity, reported Lutz Buellesfeld, MD, from Bern University Hospital in Switzerland, and colleagues.
The sinus of Valsalva also was smaller in women, but dimensions of the ascending aorta were of "similar magnitude," according to the study reported online in JACC: Cardiovascular Imaging.
Researchers found no correlation between "annulus size and distance to the coronary ostia and no association between the heights of both coronary ostia."
"[A] precise understanding of aortic root anatomy" is necessary to avoid complications "such as embolization, parvalvular regurgitation, annulus rupture, or atrioventricular conduction block," they concluded
FDA OKs Tiny Man-Made Heart
The FDA has granted two Humanitarian Use Device designations for a small artificial heart.
The 50 cc Total Artificial Heart from SynCardia Systems can now be used for destination therapy in smaller adults, particularly women (body surface area between 1.2 and 1.79 m2) or as a bridge to transplant in children who can sufficiently accommodate the device.
This model is a smaller version of the 70 cc temporary Total Artificial Heart, which received FDA approval as a bridge to transplant in 2004.
The humanitarian use designation is for a disease or condition that affects or is manifested in fewer than 4,000 individuals in the U.S per year.
Sudden Death Risk Refined with MRI
Cardiac MRI-detected fibrosis may help identify patients at high risk of sudden cardiac death who may need an implantable cardioverter defibrillator (ICD), researchers said in JACC: Cardiovascular Imaging.
A total of 204 patients with sustained ventricular tachycardia (VT) and 169 with nonsustained VT were followed for a median of 2.6 years, reported Dana K. Dawson, DM, DPhil, of the University of Aberdeen in Scotland, and colleagues.
Overall, the presence of myocardial fibrosis independently predicted the combined endpoint of cardiac death, cardiac arrest, new episode of sustained VT, ventricular fibrillation, or appropriate therapy from an ICD.
In those with sustained VT, fibrosis and an ejection fraction of 35% or below predicted the endpoint, but fibrosis was a stronger predictor. These results could refine the criteria for secondary prevention, as post-hoc analyses of landmark studies have identified patients at low risk that may not benefit from an ICD.
In those with a previous episode of nonsustained VT, fibrosis was the only independent predictor. Researchers said this finding could open "new avenues of consideration for primary prevention in groups that are not included by guidelines ...."