Could the nitroglycerin patch make abdominal swelling worse over time?

The short version: no evidence in this retrieval shows the nitroglycerin patch directly worsens abdominal swelling, but the mechanism of long-term use points toward fluid retention, and the real cause of the big stomach is still unexplained.

The studies here do not test your situation. They cover angina, preeclampsia, and heart failure, not a patient with five stents, prior open-heart surgery, and a large abdomen facing another operation [1, 2, 3]. One study on patch tolerance in angina patients is the closest match: after 24 hours of continuous use, body weight rose and hematocrit fell, which means plasma volume expanded [4]. That is fluid retention. If your abdominal swelling is from heart failure, a patch that retains fluid could make it worse over time, not better.

The patch also loses its effect with continuous use. The same tolerance study shows clinical efficacy fades after 24 hours while the arterial dilation persists [4]. So you get the side effects, including fluid shifts, without the sustained benefit. Chronic nitroglycerin also damages the blood vessel lining itself, a 2011 animal study shows, through oxidative stress and enzyme disruption [5]. That is a long-term cost, not a short-term one.

What the retrieval cannot see matters more than what it shows. No study here compares the patch to no treatment in someone with your exact cardiac history. No study tracks abdominal girth as an outcome. The manufacturer funded none of these trials, but the absence of a direct safety study is the finding. The big stomach needs its own workup, ascites versus liver congestion versus obesity, before the patch is the right call.

My call: the patch is a symptom measure, not a treatment for the swelling, and its fluid-retaining effect makes it a plausible contributor if the swelling is cardiac. Confidence: low, because the evidence does not match this patient.