ECG left ventricular hypertrophy: A good omen before TAVR?
Patients without electrocardiographic (ECG) evidence of left ventricular hypertrophy were significantly more likely to die in the two years after transcatheter aortic valve replacement (TAVR), researchers reported July 30 in Clinical Cardiology.
“Left ventricular hypertrophy identified by ECG has been associated with worse outcomes in hypertensive patients, as well as asymptomatic aortic stenosis (AS),” wrote lead author Polydoros N. Kampaktsis, MD, with Weill Cornell Medical College in New York, and colleagues. “However, in elderly patients with AS that undergo TAVR, adverse concurrent pathophysiologic mechanisms such as amyloidosis or myocardial fibrosis can lead to decreased ECG voltage.”
The researchers studied 231 patients who underwent TAVR at a single center between March 2009 and December 2014. Participants were an average of 84.7 years old, 42 percent were male and 43 percent met Cornell voltage criteria for ECG LVH.
At two years, patients with ECG LVH demonstrated significantly lower mortality rates, 23.6 percent versus 40.4 percent. Upon multivariable adjustment, the absence of ECG LVH was associated 79 percent increased odds of mortality.
“To our knowledge, this is the first study to examine the relationship of baseline ECG LVH to mortality after TAVR,” Kampaktsis et al. reported. “During a mean follow-up time of 16.3±10.4 months after TAVR, those patients without ECG LVH had nearly twice the adjusted mortality risk of those who met Cornell voltage criteria independently of other univariate baseline predictors of mortality in our cohort as well as LVMI (left ventricular mass index), suggesting that any impact of ECG LVH on mortality was distinct from myocardial hypertrophy.”
Also, known periprocedural TAVR complications associated with mortality weren’t significantly different between groups, the authors pointed out.
Kampaktsis and coauthors said cardiac amyloidosis, which is associated with advanced age and restrictive physiology, could have explained the increased mortality in patients without LVH.
In addition, patients without ECG LVH had near triple the rates of myocardial infarction before study enrollment. Although the authors attempted to adjust for this factor, they noted “it is conceivable that those without ‘electrical remodeling’ were more likely to have unreported ‘silent’ infarctions or increased burden of microvascular disease at baseline, which could have contributed to higher mortality after TAVR.”
Finally, it is unknown whether the results of this single-center study would translate to younger populations.
“Further studies with larger patient cohorts are required to examine whether low QRS voltage, particularly the lack of ECG LVH, carries worse prognosis in patients undergoing TAVR,” the researchers wrote. “If that is truly the case, the presence of cardiac amyloidosis or myocardial fibrosis could be explored as potential underlying mechanisms.”
Daniel joined TriMed’s Chicago editorial team in 2017 as a Cardiovascular Business writer. He previously worked as a writer for daily newspapers in North Dakota and Indiana.