From the Guidelines
Nitroglycerin can improve renal blood flow in heart failure patients, particularly those with acute decompensated heart failure, by reducing cardiac preload and pulmonary congestion, and improving forward blood flow to organs including the kidneys. When administered at low doses (typically starting at 0.3-0.5 mcg/kg/min IV and titrated as needed), nitroglycerin primarily causes venodilation, which can decrease central venous pressure and renal venous congestion, and improve cardiac output 1. At higher doses (>2 mcg/kg/min), it also produces arterial vasodilation, which can decrease systemic vascular resistance and further improve forward blood flow to organs including the kidneys. However, clinicians should monitor blood pressure carefully during administration, as excessive hypotension could paradoxically worsen renal perfusion. The effect is most beneficial in patients with volume overload and elevated filling pressures, while those with hypotension or severe renal dysfunction may not experience the same benefits.
Some key points to consider when using nitroglycerin in heart failure patients include:
- Initial recommended dose of i.v. nitroglycerin is 10 – 20 mg/min, increased in increments of 5 – 10 mg/min every 3 – 5 min as needed 1
- Slow titration of i.v. nitrates and frequent BP measurement is recommended to avoid large drops in SBP 1
- An arterial line is not routinely required but will facilitate titration in patients with borderline pressures 1
- Nitroglycerin's effects are relatively short-acting, making it suitable for acute management but not for long-term improvement in renal function.
It's also important to note that the use of nitroglycerin in heart failure patients has been supported by several studies, including a Class II study that found high-dose nitrates used in combination with low-dose furosemide to be a more effective treatment regimen in acute heart failure than low-dose nitrates combined with high-dose furosemide 1. Additionally, a retrospective analysis of registry data found that treatment with intravenous nitroglycerin significantly reduced in-hospital mortality compared with that of patients who received inotropic therapy with either milrinone or dobutamine 1.
From the Research
Nitroglycerin and Renal Blood Flow in Heart Failure
- The effect of nitroglycerin on renal blood flow in heart failure patients is not directly addressed in the provided studies 2, 3, 4, 5, 6.
- However, the studies suggest that nitroglycerin can have beneficial effects on hemodynamics and cardiac function in patients with heart failure, which may indirectly affect renal blood flow 3, 5.
- For example, a study published in 2004 found that intravenous nitroglycerin can lead to beneficial hemodynamic effects, such as reduction of mitral regurgitation and improvement of myocardial ischemia, in patients with acute decompensated heart failure 3.
- Another study published in 2015 found that intravenous nitroglycerin can reduce left ventricular and right ventricular filling pressures and afterload, which may improve cardiac output and potentially increase renal blood flow 5.
- However, the studies also note that the use of nitroglycerin in heart failure patients can be limited by the development of nitrate tolerance and decreased vasodilatory response, which may affect its efficacy in improving renal blood flow 3, 5.
Key Findings
- Nitroglycerin can have beneficial effects on hemodynamics and cardiac function in patients with heart failure 3, 5.
- The use of nitroglycerin in heart failure patients can be limited by the development of nitrate tolerance and decreased vasodilatory response 3, 5.
- Early prehospital administration of intravenous nitroglycerin may be associated with lower mortality and post-discharge events in patients with acute heart failure 6.