Cell Strikethough - Check For

This seems such a simple problem, but I have Googled myself to a standstill.

I wish to return the contents of an Excel cell, and check whether the font has a Strikethrough property. This is my flag to ignore that row. I am using ClosedXML and the following code: 

XLWorkbook wb = new XLWorkbook(fs);
IXLWorksheet ws = wb.Worksheet(pstrXLSWorksheetName);
if (ws.Cell(lstrCellAddressPriKey).Style.Font.Strikethrough == true)
{
pintTotalStrikethroughsIgnored++;
lblnProceed = false;
}

This works but the performance is appalling. Over severall hundred rows it turns a minute into an hour.

Can anyone provide a sample not using ClosedXML?
bool IsStrikethrough(cell) - or (cellAddress)

Thanks

Dale