Results
A total weighted estimate of 25,503 hospitalizations for LVAD implantation were identified during 2011 to 2017. Average age of the entire cohort was 57 ±13 years, with a median of 59 years, ranging from 18 to 90 years. Female gender accounted for 23% (n=5,820) of the total population. The high-income group comprised 47% (n=11,907) of the cohort and the low-income group represented 53% (n=13,595) (See Table 1). All comparisons henceforth are reported as low-income versus (vs.) high-income for consistency. We found an average increased rate of LVAD implantation from 2011 to 2017 of 11% for the low-income group and 8% for higher income individuals (See Figure A).
Low-income group mean age was significantly lower (55±14 vs. 58±13, p<0.001), with an increased proportion of females (24% vs. 22%, p<0.001) when compared to the high-income group. Patients with higher income are more likely to be from suburbs of metro areas of ≥ 1 million population (13% vs. 42%, p<0.001) and self-identified as White (57% vs. 70%, p<0.001). In term of comorbidities, the low-income group was found to have significantly higher proportions of hypertension (41% vs. 37%, p<0.001), smoking (28% vs. 24%, p<0.001), anemia (7% vs. 6%, p<0.001), dyslipidemia (39% vs. 35%, p<0.001), obesity (18% vs. 15%, p<0.001) and pulmonary hypertension (41% vs. 36%, p<0.001). However, the high-income group had increased rates of atrial tachyarrhythmias including atrial fibrillation and atrial flutter (48% vs. 50%, p<0.001) and history of coronary artery bypass graft (9% vs. 11%, p<0.001). There were no significant differences found in diabetes, alcohol and substance abuse, malnutrition, prior strokes, coronary artery disease, peripheral artery disease, chronic kidney disease, chronic liver disease, history of percutaneous coronary intervention or obstructive sleep apnea between both groups.
However, in the high-income group, we found significantly longer hospital stay (median 29 [20-42] vs. 29 [20-44] days, p<0.001) (See Figure B), higher hospital charges (median $770,852 [544,193-1,135,933] vs. $727,922 [539,402-1,034,619], p<0.001), increased proportion of post procedure strokes (5.6% vs. 8.3%, p<0.001) with ischemic strokes comparison of 4% vs. 7% (p<0.001), acute kidney injury (59% vs. 63%, p<0.001), bleeding (29% vs. 33%, p<0.001) and need of extracorporeal membrane oxygenation (6% vs. 8%, p<0.001) (see Table 2).
No significant differences were found in the incidences of ventricular arrhythmias, blood product transfusions, pericardial complications, postoperative deep venous thrombosis and pulmonary embolism, LVAD thrombosis or embolism between groups. There was a decreased rate of in-hospital mortality in patients undergoing LVAD from 2011 to 2017 in both groups (See Figure C).
Combining data from all years (2011–2017), high-income was associated with higher post-LVAD all-cause inpatient mortality (odds ratio (OR) 1.303; 95%, confidence interval (CI) 1.207–1.407; p<0.001) that remained significant beyond adjustment for demographic factors and comorbidities (OR 1.178; 95% CI 1.085–1.280; p<0.001).