RESUMEN
Long COVID refers to a multitude of symptoms that persist long after SARS-CoV-2 infection. Fatigue and breathlessness are the most common symptoms of long COVID across a range of studies. They are also cardinal symptoms of chronic heart failure (CHF). In this review, we propose that fatigue and breathlessness in patients with long COVID may be explained by skeletal muscle abnormalities, in a manner similar to patients with CHF. The ergoreflex is a cardiorespiratory reflex activated by exercise, which couples ventilation and cardiovascular function to exercise intensity. At least part of the symptomatology of CHF is related to abnormal skeletal muscle and an enhanced ergoreflex, resulting in heightened sympathetic, vasoconstrictor and ventilator drives. Similarly, SARS-CoV-2 infection results in a hyperinflammatory and hypercatabolic state. This leads to reduction in skeletal muscle mass and altered function. We postulate that the ergoreflex is chronically overstimulated, resulting in fatigue and breathlessness. Exercise training preserves muscle mass and function as well as reduces ergoreflex activation; therefore may have a role in improving symptoms associated with long COVID. Should the ergoreflex be proven to be an important pathophysiological mechanism of long COVID, tailored exercise interventions should be trialed with the aim of improving both symptoms and perhaps outcomes in patients with long COVID.
RESUMEN
AIMS: Uncontrolled blood pressure (BP) increases the risk of developing heart failure (HF). The effect of spironolactone on BP of patients at risk of developing HF is yet to be determined. To evaluate the effect of spironolactone on the BP of patients at risk for HF and whether renin can predict spironolactone's effect. METHODS AND RESULTS: HOMAGE (Heart OMics in Aging) was a prospective multicentre randomized open-label blinded endpoint (PROBE) trial including 527 patients at risk for developing HF randomly assigned to either spironolactone (25-50 mg/day) or usual care alone for a maximum of 9 months. Sitting BP was assessed at baseline, Months 1 and 9 (or last visit). Analysis of covariance (ANCOVA), mixed effects models, and structural modelling equations was used. The median (percentile25-75) age was 73 (69-79) years, 26% were female, and >75% had history of hypertension. Overall, the baseline BP was 142/78 mmHg. Patients with higher BP were older, more likely to have diabetes and less likely to have coronary artery disease, had greater left ventricular mass (LVM), and left atrial volume (LAV). Compared with usual care, by last visit, spironolactone changed SBP by -10.3 (-13.0 to -7.5) mmHg and DBP by -3.2 (-4.8 to -1.7) mmHg (P < 0.001 for both). A higher proportion of patients on spironolactone had controlled BP <130/80 mmHg (36 vs. 26%; P = 0.014). Lower baseline renin levels predicted a greater response to spironolactone (interactionP = 0.041). CONCLUSION: Spironolactone had a clinically important BP-lowering effect. Spironolactone should be considered for lowering blood pressure in patients who are at risk of developing HF.