BACKGROUND: Coronary microvascular dysfunction (CMD) is involved in heart failure (HF) onset and progression, independently of HF phenotype and obstructive coronary artery disease. Invasive assessment of CMD might provide insights into phenotyping and prognosis of patients with HF. We aimed to assess absolute coronary flow, absolute microvascular resistance, myocardial perfusion, coronary flow reserve, and microvascular resistance reserve in patients with HF with preserved ejection fraction and HF with reduced ejection fraction (HFrEF). METHODS: Single-center, prospective study of 56 consecutive patients with de novo HF with nonobstructive coronary artery disease divided into HF with preserved ejection fraction (n=21) and HFrEF (n=35). CMD was invasively assessed by continuous intracoronary thermodilution and defined as coronary flow reserve <2.5. Left ventricular and left anterior descending artery–related myocardial mass was quantified by echocardiography and coronary computed tomography angiography. Myocardial perfusion (mL/min per g) was calculated as the ratio between absolute coronary flow and left anterior descending artery–related mass. RESULTS: Patients with HFrEF showed a higher left ventricular and left anterior descending artery–related myocardial mass compared with HF with preserved ejection fraction ( P <0.010). Overall, 52% of the study population had CMD, with a similar prevalence between the 2 groups. In HFrEF, CMD was characterized by lower absolute microvascular resistance and higher absolute coronary flow at rest (functional CMD; P =0.002). CMD was an independent predictor of a lower rate of left ventricular reverse remodeling at follow-up. In patients with HF with preserved ejection fraction, CMD was mainly due to higher absolute microvascular resistance and lower absolute coronary flow during hyperemia (structural CMD; P ≤0.030). CONCLUSIONS: Continuous intracoronary thermodilution allows the definition and characterization of patterns with distinct CMD in patients with HF and could identify patients with HFrEF with a higher rate of left ventricular reverse remodeling at follow-up.

Absolute coronary flow can be measured by intracoronary continuous thermodilution of saline through a dedicated infusion catheter (RayFlow®). A saline infusion rate at 15-20 mL/min induces an immediate, steady-state, maximal microvascular vasodilation. The mechanism of this hyperemic response remains unclear. We aimed to test whether local hemolysis is a potential mechanism of saline-induced coronary hyperemia. Twelve patients undergoing left and right catheterization were included. The left coronary artery and the coronary sinus were selectively cannulated. Absolute resting and hyperemic coronary flow were measured by continuous intracoronary thermodilution. Arterial and venous samples were collected from the coronary artery and the coronary sinus in five phases: baseline (BL); resting flow measurement (Rest, saline infusion at 10 mL/min); hyperemia (Hyperemia, saline infusion at 20 mL/min); post-hyperemia (Post-Hyperemia, 2 min after the cessation of saline infusion); and control phase (Control, during infusion of saline through the guide catheter at 30 mL/min). Hemolysis was visually detected only in the centrifugated venous blood samples collected during the Hyperemia phase. As compared to Rest, during Hyperemia both LDH (131.50 ± 21.89 U/dL [Rest] and 258.33 ± 57.40 U/dL [Hyperemia], p < 0.001) and plasma free hemoglobin (PFHb, 4.92 ± 3.82 mg/dL [Rest] and 108.42 ± 46.58 mg/dL [Hyperemia], p < 0.001) significantly increased in the coronary sinus. The percentage of hemolysis was significantly higher during the Hyperemia phase (0.04 ± 0.02% [Rest] vs 0.89 ± 0.34% [Hyperemia], p < 0.001). Saline-induced hyperemia through a dedicated intracoronary infusion catheter is associated with hemolysis. Vasodilatory compounds released locally, like ATP, are likely ultimately responsible for localized microvascular vasodilation.

Lung ultrasonography (LUS) has become in the last 10 years a technique that has reduced the need of second level diagnostic methods such as chest X-ray (CXR) and computerize tomography (CT) for the diagnostic imaging of lung and pleural space, throughout its diagnostic accuracy, radiation free, low cost, real time and bedside approach. The common use of LUS has been recently extend to cardiac and pulmonary disease even in context of Cardiac Rehabilitation Unit and it could be an additional tool for physiotherapist for the management of patients during Rehabilitation course. The authors performed a literature review in PubMed and suggested a new standardize protocol for LUS, based on guidelines and expert consensus document, for patients admitted to Cardiac Rehabilitation Unit. In this protocol, LUS should be performed in six scan each hemithorax, covering twelve imagine regions. For each scan will be noted a specific physiologic or pathological patterns. Furthermore, we suggest for each patient, the use of the Lung Ultrasound Score (LUS score) to obtain a global view of lung aeration and to monitor any changes during the hospitalization. An increase in score range indicates a more severe condition. This Lung Ultrasonography Protocol should be performed in all patients at the time of admission to Cardiac Rehabilitation Unit to monitoring the aeration of the lungs and the possible lung and/or pleura complications after a cardiac disease avoiding the use of second level surveys.

Background: Deferring revascularization in patients with nonsignificant stenoses based on fractional flow reserve (FFR) is associated with favorable clinical outcomes up to 15 years. Whether this holds true in patients with reduced left ventricular ejection fraction is unclear. We aimed to investigate whether FFR provides adjunctive clinical benefit compared with coronary angiography in deferring revascularization of patients with intermediate coronary stenoses and reduced left ventricular ejection fraction. Methods and Results: Consecutive patients with reduced left ventricular ejection fraction (≤50%) undergoing coronary angiography between 2002 and 2010 were screened. We included patients with at least 1 intermediate coronary stenosis (diameter stenosis ≥40%) in whom revascularization was deferred based either on angiography plus FFR (FFR guided) or angiography alone (angiography guided). The primary end point was the cumulative incidence of all‐cause death at 10 years. The secondary end point (incidence of major adverse cardiovascular and cerebrovascular events) was a composite of all‐cause death, myocardial infarction, any revascularization, and stroke. A total of 840 patients were included (206 in the FFR‐guided group and 634 in the angiography‐guided group). Median follow‐up was 7 years (interquartile range, 3.22–11.08 years). After 1:1 propensity‐score matching, baseline characteristics between the 2 groups were similar. All‐cause death was significantly lower in the FFR‐guided group compared with the angiography‐guided group (94 [45.6%] versus 119 [57.8%]; hazard ratio [HR], 0.65 [95% CI, 0.49–0.85]; P <0.01). The rate of major adverse cardiovascular and cerebrovascular events was lower in the FFR‐guided group (123 [59.7%] versus 139 [67.5%]; HR, 0.75 [95% CI, 0.59–0.95]; P =0.02). Conclusions: In patients with reduced left ventricular ejection fraction, deferring revascularization of intermediate coronary stenoses based on FFR is associated with a lower incidence of death and major adverse cardiovascular and cerebrovascular events at 10 years.