RESUMO
Introduction: Both coronary flow reserve (CFR) and chronic kidney disease (CKD) are known to be associated with adverse cardiac events. However, it is unclear how these prognostic factors are interrelated. This study evaluated the association between intracoronary physiologic indexes and CKD and their prognostic implications. Methods: A total of 351 patients without left ventricular systolic dysfunction (ejection fraction ≥ 40%) and not on dialysis whose revascularization was deferred based on fractional flow reserve (FFR) > 0.80 were analyzed. Depressed CFR was defined as CFR ≤ 2.0. The primary outcome was a composite of cardiac death or hospitalization for heart failure at 3 years. Results: Patients with CKD showed lower CFR than the non-CKD population (3.28 ± 1.77 vs. 2.60 ± 1.09, P < 0.001), mainly driven by increased resting coronary flow. There was no significant difference in hyperemic coronary flow, FFR, and index of microvascular resistance between the 2 groups. CFR was significantly associated with estimated glomerular filtration rate (eGFR) (P = 0.045), and the proportion of depressed CFR was significantly increased with higher CKD stages (P = 0.011). The risk of cardiac death or hospitalization for heart failure was the lowest in the non-CKD and preserved CFR group (11.9%) and the highest in the CKD and depressed CFR group (60.0%, overall log rank P < 0.001). Both CKD (adjusted hazard ratio [HRadj] 2.614, 95% confidence interval [CI] 1.505-4.539, P < 0.001) and depressed CFR (HRadj 3.237, 95% CI 2.015-5.199, P < 0.001) were independently associated with the risk of the primary outcome. Conclusion: There was a significant association between severity of CKD and CFR. Both CKD and depressed CFR showed independent association with higher risk of cardiac death or hospitalization for heart failure.
RESUMO
BACKGROUND: Cardiac diastolic dysfunction is an independent predictor of mortality, regardless of left ventricular (LV) systolic function. However, the current guidelines that define cardiac diastolic dysfunction may underrate the clinical implications of those with indeterminate diastolic function. OBJECTIVES: We sought to evaluate the prognostic implications of indeterminate diastolic function on echocardiography and its association with coronary microvascular dysfunction (CMD). METHODS: A total of 330 patients without LV systolic dysfunction and significant epicardial coronary stenosis (fractional flow reserve > 0.80) were analyzed from a prospective registry. Cardiac diastolic dysfunction was defined according to 2 algorithms depending on the presence of myocardial disease. First, the presence of myocardial disease and evidence of elevated LV filling pressure indicated diastolic dysfunction. Second, diastolic function in those without myocardial disease was defined using echocardiographic parameters (E/e', e' velocity, tricuspid regurgitation velocity, and left atrial volume index). Patients who did not meet half of the available criteria were classified as having indeterminate diastolic function. Coronary microvascular dysfunction was defined as coronary flow reserve < 2.0 and index of microcirculatory resistance ≥ 25 U. The primary outcome was cardiovascular death or admission for heart failure at 5 years. RESULTS: Coronary flow reserve was lower in patients with indeterminate diastolic function compared with those with no diastolic dysfunction (3.5 ± 1.6 vs 3.2 ± 1.6, P = .002). The prevalence of CMD was also higher in patients with indeterminate diastolic function than in those with no diastolic dysfunction (10.6% vs 4.9%, P < .034). Patients with indeterminate diastolic function showed significantly higher risk of cardiovascular death or admission for heart failure than those without indeterminate diastolic function but not greater than those with definite diastolic dysfunction (cumulative incidence: 12.6%, 27.2%, and 32.7%, respectively, log-rank P < .001). Presence of CMD and elevated LV filling pressure (E/e' > 14) were independent predictors for cardiovascular death or admission for heart failure in patients with indeterminate diastolic function. CONCLUSIONS: Patients with indeterminate diastolic function on echocardiogram showed higher risk of cardiovascular death or admission for heart failure than those with no diastolic dysfunction. Presence of CMD and elevated LV filling pressure were independent predictors for cardiovascular death or admission for heart failure among patients with indeterminate diastolic function.
